太田　直美OTA Naomiオオタ　ナオミ

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プロフィール情報

• 姓

  太田, オオタ

• 名

  直美, ナオミ

学位

• 博士(理学), 東京大学

研究キーワード

• X線天文学
• 宇宙物理学
• 銀河団
• 構造形成
• X線詳細分光
• 観測的宇宙論

研究分野

• 自然科学一般, 素粒子、原子核、宇宙線、宇宙物理にする理論
• 自然科学一般, 天文学

経歴

• 2010年, 2014年, 奈良女子大学理学部物理科学科助教
• 2010年, 2014年, Assistant professor, Department of Physics, Nara Women's University
• 2014年, 奈良女子大学自然科学系物理学領域
• 2014年, Assosiate professor, Department of Physics, Nara Women's University
• 2009年, 2010年, :東京理科大学理学部第一部物理学科助教
• 2009年, 2010年, :Assistant professor, Department of Physics, Tokyo University of Science
• 2007年, 2009年, :フンボルト財団奨学研究員
• 2007年, 2009年, :JAXA 宇宙航空プロジェクト研究員
• 2007年, 2009年, :Humboldt Research Fellow
• 2007年, 2009年, :JAXA Aerospace Project Research Associate
• 2004年, 2007年, :理化学研究所 基礎科学特別研究員
• 2004年, 2007年, :RIKEN Special Postdoctoral Researcher
• 2001年, 2004年, :日本学術振興会特別研究員(PD)
• 2001年, 2004年, :JSPS Postdoctoral Research Fellow
• 1998年, 2001年, :日本学術振興会特別研究員(DC1)
• 1998年, 2001年, :JSPS Research Fellow

学歴

• 2001年, 東京大学, 理学系研究科, 物理学, 日本国
• 2001年, 東京大学, Graduate School, Division of Science, Physics, 日本国
• 1996年, 東京大学, 理学部, 物理学科, 日本国
• 1996年, 東京大学, Faculty of Science, Department of Physics, 日本国

所属学協会

• International Astronomical Union
• 高エネルギー宇宙物理連絡会
• 日本物理学会
• 日本天文学会
• International Astronomical Union
• High Energy Astrophysics Association in Japan
• The Physical Society of Japan
• The Astronomical Society of Japan

メディア報道

• 銀河と銀河をつなぐ宇宙で最長のガスフィラメントの発見, 本人, 奈良女子大学、ボン大学, 2020年12月, http://www.nara-wu.ac.jp/nwu/news/2020news/20201217/20201217.html, インターネットメディア, 31497633, rm:research_project_id

  対象リソースIRI

Ⅱ．研究活動実績

論文

• 査読あり, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Halo concentration, galaxy red fraction, and gas properties of optically defined merging clusters, Nobuhiro Okabe; Masamune Oguri; Hiroki Akamatsu; Akinari Hamabata; Atsushi J. Nishizawa; Elinor Medezinski; Yusei Koyama; Masao Hayashi; Taizo Okabe; Shutaro Ueda; Ikuyuki Mitsuishi; Naomi Ota, We present multi-wavelength studies of optically defined merging clusters, based on the Hyper Suprime-Cam Subaru Strategic Program. Luminous red galaxies, tracing cluster mass distributions, enable us to identify cluster subhalos at various merging stages, and thus make a homogeneous sample of cluster mergers that is unbiased with respect to the merger boost of the intracluster medium (ICM). We define, using a peak-finding method, merging clusters with multiple peaks and single clusters with single peaks from the CAMIRA cluster catalog. Stacked weak-lensing analysis indicates that our sample of merging clusters is categorized into major mergers. The average halo concentration for the merging clusters is similar to 70% smaller than that of the single-peak clusters, which agrees well with predictions of numerical simulations. The spatial distribution of subhalos is less centrally concentrated than the mass distribution of the main halo. The fractions of red galaxies in the merging clusters are not higher than those of the single-peak clusters. We find a signature of the merger boost of the ICM from the stacked Planck Sunyaev-Zel'dovich effect and ROSAT X-ray luminosity, but not in optical richness. The stacked X-ray surface brightness distribution, aligned with the main subhalo pairs of low-redshift and massive clusters, shows that the central gas core is elongated along the merger axis, and overall gas distribution is misaligned by similar to 60 degrees. The homogeneous, unbiased sample of cluster mergers and multi-wavelength follow-up studies provide a unique opportunity to make a complete picture of merger physics over the whole process., 2019年08月, 71, 4, 研究論文（学術雑誌）, 10.1093/pasj/psz059

  DOI URL
• 査読無し, 英語, Proc. SPIE 10699, Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray, Super DIOS: future x-ray spectroscopic mission to search for dark baryons, T. Ohashi; Y. Ishisaki; Y. Ezoe; S. Yamada; R. Hayakawa; K. Nunomura; K. Sato; Y. Tawara; I. Mitsuishi; K. Ohtsuka; K. Mitsuda; N. Y. Yamasaki; T. Kikuchi; T. Hayashi; H. Muramatsu; Y. Nakashima; N. Ota; K. Osato; Y. Ichinohe; M. E. Eckart; S. R. Bandler; R. L. Kelley; C. A. Kilbourne, 2018年07月06日, 研究論文（国際会議プロシーディングス）, 10.1117/12.2313122

  DOI URL
• 査読無し, 英語, JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS, Hitomi (ASTRO-H) X-ray Astronomy Satellite, Tadayuki Takahashi; Motohide Kokubun; Kazuhisa Mitsuda; Richard L. Kelley; Takaya Ohashi; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Makoto Asai; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Philipp Azzarello; Chris Baluta; Aya Bamba; Nobutaka Bando; Marshall W. Bautz; Thomas Bialas; Roger Blandford; Kevin Boyce; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Edgar Canavan; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Steve O' Dell; Michael DiPirro; Chris Done; Tadayasu Dotani; John Doty; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Stefan Funk; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Kirk Gilmore; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Daniel Haas; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Takayuki Hayashi; Katsuhiro Hayashi; Kiyoshi Hayashida; Jan-Willem den Herder; Junko S. Hiraga; Kazuyuki Hirose; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Yoshitaka Ishisaki; Masayuki Itoh; Masachika Iwai; Naoko Iwata; Naoko Iyomoto; Chris Jewell; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Erin Kara; Jun Kataoka; Satoru Katsuda; Junichiro Katsuta; Madoka Kawaharada; Nobuyuki Kawai; Taro Kawano; Shigeo Kawasaki; Dmitry Khangulyan; Caroline A. Kilbourne; Mark Kimball; Ashley King; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Saori Konami; Tatsuro Kosaka; Alex Koujelev; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Candace Masters; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Daniel Mcguinness; Brian R. McNamar; Missagh Mehdipour; Joseph Miko; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kenji Minesugi; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Franco Moroso; Harvey Moseley; Theodore Muench; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard F. Mushotzky; Housei Nagano; Ryo Nagino; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Toshio Nakano; Shinya Nakashima; Kazuhiro Nakazawa; Yoshiharu Namba; Chikara Natsukari; Yusuke Nishioka; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Masaharu Nomachi; Hirokazu Odaka; Hiroyuki Ogawa; Mina Ogawa; Keiji Ogi; Masanori Ohno; Masayuki Ohta; Takashi Okajima; Atsushi Okamoto; Tsuyoshi Okazaki; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Arvind Parmar; Robert Petre; Ciro Pinto; Jelle de Plaa; Martin Pohl; James Pontius; Frederick S. Porter; Katja Pottschmidt; Brian Ramsey; Christopher Reynolds; Helen Russell; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Shin-ichiro Sakai; Hiroaki Sameshima; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Yoichi Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Yasuko Shibano; Maki Shida; Megumi Shidatsu; Takanobu Shimada; Keisuke Shinozaki; Peter Shirron; Aurora Simionescu; Cynthia Simmons; Randall K. Smith; Gary Sneiderman; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Hiroyuki Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Keisuke Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shiro Ueno; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Cor P. de Vries; Atsushi Wada; Shin Watanabe; Tomomi Watanabe; Norbert Werner; Daniel R. Wik; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Takahiro Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Atsumasa Yoshida; Takayuki Yuasa; Irina Zhuravleva; Abderahmen Zoghbi, The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License., 2018年04月, 4, 2, 021402, 研究論文（学術雑誌）, 10.1117/1.JATIS.4.2.021402

  DOI URLScopus URLScopus Citedby URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Hitomi X-ray studies of giant radio pulses from the Crab pulsar, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle De Plaa; Cor P. De Vries; Jan-Willem Den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Kenya Oshimizu; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shinichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Toshio Terasawa; Mamoru Sekido; Kazuhiro Takefuji; Eiji Kawai; Hiroaki Misawa; Fuminori Tsuchiya; Ryo Yamazaki; Eiji Kobayashi; Shota Kisaka; Takahiro Aoki, To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2-300 keV band and the Kashima NICT radio telescope in the 1.4-1.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 sigma fluctuations of the X-ray fluxes at the pulse peaks, and the 3 sigma upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2-300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.5-10 keV and 70-300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) x 10(-11) erg cm(-2), respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magneto-sphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a > 0.02% brightening of the pulse-peak flux under such conditions., 2018年03月, 70, 2, id.15, 研究論文（学術雑誌）, 10.1093/pasj/psx083

  DOI URLScopus URLScopus Citedby URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Multiwavelength study of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program S16A field (vol 70, S22, 2018), Keita Miyaoka; Nobuhiro Okabe; Takao Kitaguchi; Masamune Oguri; Yasushi Fukazawa; Rachel Mandelbaum; Elinor Medezinski; Yasunori Babazaki; Atsushi J. Nishizawa; Takashi Hamana; Yen-Ting Lin; Hiroki Akamatsu; I-Non Chiu; Yutaka Fujita; Yuto Ichinohe; Yutaka Komiyama; Toru Sasaki; Motokazu Takizawa; Shutaro Ueda; Keiichi Umetsu; Jean Coupon; Chiaki Hikage; Akio Hoshino; Alexie Leauthaud; Kyoko Matsushita; Ikuyuki Mitsuishi; Hironao Miyatake; Satoshi Miyazaki; Surhud More; Kazuhiro Nakazawa; Naomi Ota; Kousuke Sato; David Spergel; Takayuki Tamura; Masayuki Tanaka; Manobu M. Tanaka; Yousuke Utsumi, We present a joint X-ray, optical, and weak-lensing analysis for X-ray luminous galaxy clusters selected from the MCXC (Meta-Catalog of X-Ray Detected Clusters of Galaxies) cluster catalog in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey field with S16A data. As a pilot study for a series of papers, we measure hydrostatic equilibrium (HE) masses using XMM-Newton data for four clusters in the current coverage area out of a sample of 22 MCXC clusters. We additionally analyze a non-MCXC cluster associated with one MCXC cluster. We show that HE masses for the MCXC clusters are correlated with cluster richness from the CAMIRA catalog, while that for the non-MCXC cluster deviates from the scaling relation. The mass normalization of the relationship between cluster richness and HE mass is compatible with one inferred by matching CAMIRA cluster abundance with a theoretical halo mass function. The mean gas mass fraction based on HE masses for the MCXC clusters is (fgas) = 0.125 ± 0.012 at spherical overdensity Δ = 500, which is ∼80%-90% of the cosmic mean baryon fraction, Ωb/Ωm,measured by cosmicmicrowave background experiments. We find that themean baryon fraction estimated from X-ray and HSC-SSP optical data is comparable to Ωb/Ωm. A weak-lensing shear catalog of background galaxies, combined with photometric redshifts, is currently available only for three clusters in our sample. Hydrostatic equilibrium masses roughly agree with weak-lensing masses, albeit with large uncertainty. This study demonstrates that further multi wave length study for a large sample of clusters using X-ray, HSC-SSP optical, and weak-lensing data will enable us to understand cluster physics and utilize cluster-based cosmology., 2018年06月, 70, 3, id.S22, 研究論文（学術雑誌）, 10.1093/pasj/psy024

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, A large sample of shear-selected clusters from the Hyper Suprime-Cam Subaru Strategic Program S16A Wide field mass maps, Satoshi Miyazaki; Masamune Oguri; Takashi Hamana; Masato Shirasaki; Michitaro Koike; Yutaka Komiyama; Keiichi Umetsu; Yousuke Utsumi; Nobuhiro Okabe; Surhud More; Elinor Medezinski; Yen-Ting Lin; Hironao Miyatake; Hitoshi Murayama; Naomi Ota; Ikuyuki Mitsuishi, We present the result of searching for clusters of galaxies based on weak gravitational lensing analysis of the similar to 160 deg(2) area surveyed by Hyper Suprime-Cam (HSC) as a Subaru Strategic Program. HSC is a new prime focus optical imager with a 1.(omicron)5-diameter field of view on the 8.2 m Subaru telescope. The superb median seeing on the HSC i-band images of 0 ''.56 allows the reconstruction of high angular resolution mass maps via weak lensing, which is crucial for the weak lensing cluster search. We identify 65 mass map peaks with a signal-to-noise (S/N) ratio larger than 4.7, and carefully examine their properties by cross-matching the clusters with optical and X-ray cluster catalogs. We find that all the 39 peaks with S/N > 5.1 have counterparts in the optical cluster catalogs, and only 2 out of the 65 peaks are probably false positives. The upper limits of X-ray luminosities from the ROSAT All Sky Survey (RASS) imply the existence of an X-ray underluminous cluster population. We show that the X-rays from the shear-selected clusters can be statistically detected by stacking the RASS images. The inferred average X-ray luminosity is about half that of the X-ray-selected clusters of the same mass. The radial profile of the dark matter distribution derived from the stacking analysis is well modeled by the Navarro-Frenk-White profile with a small concentration parameter value of c(500) similar to 2.5, which suggests that the selection bias on the orientation or the internal structure for our shear-selected cluster sample is not strong., 2018年01月, 70, SP1, id.S27, 研究論文（学術雑誌）, 10.1093/pasj/psx120

  DOI URL
• 査読無し, 英語, NATURE, Solar abundance ratios of the iron-peak elements in the Perseus cluster, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle De Plaa; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousine; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; StPhane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Cor P. de Vries; Shin Watanabe; Norbert Werner; Daniel R. Wik; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi, The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae(1). Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode(2-6). Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun(7-11), suggesting differences between the nature of type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, highresolution spectroscopy is required for an accurate determination of the abundances of these elements. Here we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations(12-14) disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near-and sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment(5,15,16)., 2017年11月, 551, 7681, 478, +, 研究論文（学術雑誌）, 10.1038/nature24301

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• 査読あり, 英語, Astrophysical Journal, Gas bulk motion in the perseus cluster measured with Suzaku, T. Tamura; N. Y. Yamasaki; R. Iizuka; Y. Fukazawa; K. Hayashida; S. Ueda; K. Matsushita; K. Sato; K. Nakazawa; N. Ota; M. Takizawa, We present the results from Suzaku observations of the Perseus Cluster, which is relatively close, the brightest in the X-ray sky, and a relaxed object with a cool core. A number of exposures of central regions and offset pointing with the X-ray Imaging Spectrometer cover a region within radii of 20′-30′. The central data are used to evaluate the instrumental energy-scale calibration with accuracy confirmed to within around 300 km s -1 by the spatial and temporal variation of the instruments. These deep and well-calibrated data are used to measure X-ray redshifts of the intracluster medium. A hint of gas bulk motion, with radial velocity of about -(150-300) km s-1 relative to the main system, was found at 2′-4′ (45-90 kpc) west of the cluster center, where an X-ray excess and a cold front were found previously. No other velocity structure was discovered. Over spatial scales of 50-100 kpc and within 200 kpc radii of the center, the gas-radial-velocity variation is below 300 km s-1, while over scales of 400 kpc within 600 kpc radii, the variation is below 600 km s-1. These X-ray redshift distributions are compared spatially with those of optical member galaxies for the first time in galaxy clusters. Based on X-ray line widths, gas turbulent velocities within these regions are also constrained within 1000-3000 km s-1. These results of gas dynamics in the core and larger scales in association with cluster merger activities are discussed, and the future potential of high-energy resolution spectroscopy with ASTRO-H is considered. © 2014. The American Astronomical Society. All rights reserved.., 2014年02月10日, 782, 1, 研究論文（学術雑誌）, 10.1088/0004-637X/782/1/38

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• 査読あり, 英語, Publications of the Astronomical Society of Japan, Erratum: X-ray study of the outer region of Abell 2142 with Suzaku (Publications of the Astronomical Society of Japan (2012) 63 (S1019)), Hiroki Akamatsu; Akio Hoshino; Yoshitaka Ishisaki; Takaya Ohashi; Kosuke Sato; Yoh Takei; Naomi Ota, 2012年08月25日, 64, 4, 90, 研究論文（学術雑誌）, 10.1093/pasj/64.4.90

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• 査読あり, 英語, Publications of the Astronomical Society of Japan, X-ray study of temperature and abundance profiles of the cluster of galaxies Abell 1060 with Suzaku, Kosuke Sato; Noriko Y. Yamasaki; Manabu Ishida; Yoshitaka Ishisaki; Takaya Ohashi; Hajime Kawahara; Takao Kitaguchi; Madoka Kawaharada; Motohide Kokubun; Kazuo Makishima; Naomi Ota; Kazuhiro Nakazawa; Takayuki Tamura; Kyoko Matsushita; Naomi Kawano; Yasushi Fukazawa; John P. Hughes, We carried out observations of the central and 20′ east offset regions of the cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral analysis has revealed temperature and abundance profiles of Abell 1060 out to 27′ ≃ 380 h70 -1 kpc, which corresponds to ∼ 0.25 r180. Temperature decrease of the intra-cluster medium from 3.4 keV at the center to 2.2 keV in the outskirt region was clearly observed. The abundances of Si, S, and Fe also decrease by more than 50% from the center to the outer region, while Mg shows a fairly constant abundance distribution at ∼ 0.7 solar within r ≲ 17′. O shows a lower abundance of ∼ 0.3 solar in the central region (r ≲ 6′), and indicates a similar feature with Mg however, it is sensitive to the estimated contribution of the Galactic components of k T1 ≃ 0.15 keV and k T2 ≃ 0.7 keV in the outer annuli (r ≳ 13′). Systematic effects due to the point-spread function tails, contamination on the XIS filters, instrumental background, cosmic and/or Galactic X-ray background, and the assumed solar abundance tables were carefully examined. The results on the temperature and abundances of Si, S, and Fe are consistent with those derived by XMM-Newton at r ≲ 13′. The formation and metal-enrichment process of the cluster are discussed based on the present results. © 2007. Astronomical Society of Japan., 2007年, 59, 2, 299, 317, 研究論文（学術雑誌）, 10.1093/pasj/59.2.299

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• 査読あり, 英語, IEEE Nuclear Science Symposium Conference Record, In-flight status of the X-ray observatory Suzaku, T. Dotani; K. Mitsuda; M. Bautz; H. Inoue; R. L. Kelley; K. Koyama; H. Kunieda; K. Makishima; Y. Ogawara; R. Petre; T. Takahashi; H. Tsunemi; N. E. White; N. Anabuki; L. Angelini; K. Arnaud; H. Awaki; A. Bamba; K. Boyce; G. V. Brown; K. W. Chan; J. Cottam; J. Doty; K. Ebisawa; Y. Ezoe; A. C. Fabian; E. Figueroa; R. Fujimoto; Y. Fukazawa; T. Furusho; A. Furuzawa; K. Gendreau; R. E. Griffiths; Y. Haba; K. Hamaguchi; I. Harrus; G. Hasinger; I. Hatsukade; K. Hayashida; P. J. Henry; J. S. Hiraga; S. S. Holt; A. Hornschemeier; J. P. Hughes; U. Hwang; M. Ishida; Y. Ishisaki; N. Isobe; M. Itoh; N. Iyomoto; S. M. Kahn; T. Kamae; H. Katagiri; J. Kataoka; H. Katayama; N. Kawai; M. Kawaharada; C. Kilbourne; K. Kinugasa; S. Kissel; S. Kitamoto; M. Kohama; T. Kohmura; M. Kokubun; T. Kotani; J. Kotoku; A. Kubota; G. M. Madejski; Y. Maeda; F. Makino; A. Markowitz; C. Matsumoto; H. Matsumoto; M. Matsuoka; K. Matsushita; D. McCammon; T. Mihara; K. Misaki; E. Miyata; T. Mizuno; K. Mori; H. Mori; M. Morii; H. Moseley; K. Mukai; H. Murakami; T. Murakami; R. Mushotzky; F. Nagase; M. Namiki; H. Negoro; K. Nakazawa; J. A. Nousek; T. Okajima; Y. Ogasaka; T. Ohashi; T. Oshima; N. Ota; M. Ozaki; H. Ozawa; A. N. Parmar; W. D. Pence; F. Scott Porter; J. N. Reeves; G. R. Ricker; I. Sakurai; W. T. Sanders; A. Senda; P. Serlemitsos; R. Shibata; K. Shinozaki; Y. Soong; R. Smith; M. Suzuki; A. E. Szymkowiak; H. Takahashi; Y. Takei; T. Tamagawa; K. Tamura; T. Tamura; Y. Tanaka; M. Tashiro; Y. Tawara; Y. Terada; Y. Terashima; H. Tomida; K. Torii; Y. Tsuboi; Y. Tsujimoto; T. Tsuru; M. J.L. Turner; Y. Uchiyama; Y. Ueda; S. Ueno; M. Ueno; S. Uno; Y. Urata; S. Watanabe; N. Yamamoto; K. Yamaoka; N. Y. Yamasaki; K. Yamashita; M. Yamauchi; S. Yamauchi; T. Yaqoob; D. Yonetoku; A. Yoshida, We report in-flight status of the X-ray detectors on board the Suzaku observatory, the 5th X-ray astronomy satellite of Japan launched on July 10, 2005. Suzaku is equipped with two types of Instruments: one is the X-ray Imaging Spectrometers (XISs) and the other is Hard X-ray Detector (HXD). XIS utilizes the X-ray CCD camera in combination with the grazing-incidence X-ray telescope. HXD is a non-imaging, hybrid detector utilizing Si PIN diodes and GSO/BGO phoswich counters. Suzaku takes a low-earth, circular orbit with an altitude of 560 km and an inclination of 31 deg. This means that Suzaku goes through the south atlantic anomaly about 1/3 of its revolutions. This has a large impact on the in-flight performance of XIS and HXD, which is reported in detail in the present paper. © 2007 IEEE., 2007年, 4, 2526, 2531, 研究論文（国際会議プロシーディングス）, 10.1109/NSSMIC.2007.4436667

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• 査読あり, 英語, PROCEEDINGS OF THE IAU 8TH ASIAN-PACIFIC REGIONAL MEETING, VOL I, Chandra spectroscopy and mass estimation of the lensing cluster of galaxies CL0024+17, N Ota; M Hattori; E Pointecouteau; K Mitsuda, We present the X-ray analysis and the mass estimation of the lensing cluster of galaxies CL0024+17 with Chandra. We found that the temperature profile is consistent with being isothermal and the average X-ray temperature is 4.47(-0.54)(+0.83) keV. The X-ray surface brightness profile is represented by the sum of emissions associated with the central three bright elliptical galaxies and the emission from intracluster medium (ICM), which can be well described by a spherical beta-model. Assuming the ICM to be in hydrostatic equilibrium, we estimated the X-ray mass and found it is significantly smaller than the strong lensing mass by a factor of 3., 2003年, 289, 465, 468, 研究論文（国際会議プロシーディングス）
• 査読あり, その他, IEEE Nuclear Science Symposium and Medical Imaging Conference, Spatially dependent response of thick and large area PIN diode developed for ASTRO-E hard x-ray detector, Sugiho M; Kamae T; Makishima K; Takahashi T; Murakami T; Tashiro M; Fukazawa Y; Kaneda M; Tamura T; Iyomoto N; Sugizaki M; Ozawa H; Kubota A; Nakazawa K; Yamaoka K; Kokubun M; Ota N; Tanihata C; Isobe N; Kubo S; Terada Y; Matsumoto Y; Uchiyama Y; Yonetoku D; Takahashi I; Kotoku J; Watanabe S; Ezoe Y, The ASTRO-E Hard X-ray Detector utilizes GSO/BGO well-type phoswich counters in compound-eye configuration, to achieve an extremely low background level of about a few times 10-5 counts s-1 cm-2 keV-1. The GSO scintillators placed at the bottom of the BGO well observe photons in the energy range 30-600 keV. To cover the lower energy range of 10-60 keV, silicon PIN diodes of 2 mm in thickness and 21.5 × 21.5mm2 in size were newly developed, and placed in front of the GSO scintillators. The PIN diode exhibits complex spectral responses, including subpeak and low energy tail components. To examine the origin of these components, we measured spatially-resolved response of the PIN diode, and confirmed that the subpeak and the low energy tail are related to the electrode structures and electric fields in the PIN diode, respectively., 2000年, 1, 研究論文（国際会議プロシーディングス）

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Search for the warm-hot intergalactic medium around A 2744 using Suzaku, Shiho Hattori; Naomi Ota; Yu-Ying Zhang; Hiroki Akamatsu; Alexis Finoguenov, We present the results from Suzaku satellite observations of the surrounding region of a galaxy cluster, A 2744, at z = 0.3. To search for oxygen emission lines from the warm-hot intergalactic medium (WHIM), we analyzed X-ray spectra from two northeastern regions 2.2-3.3 and 3.3-4.4 Mpc from the center of the cluster, which offers the first test on the presence of a WHIM near the typical accretion shock radius (similar to 2 r(200)) predicted by hydrodynamical simulations. For the 2.2-3.3 Mpc region, the spectral fit significantly (99.2% significance) improved when we included O-VII and O-VIII lines in the spectralmodel. A comparable WHIM surface brightness was obtained in the 3.3-4.4 Mpc region and the redshift of the O-VIII line is consistent with z=0.3 with in errors. The present results support that the observed soft X-ray emission originated from the WHIM. However, considering both statistical and systematic uncertainties, OVIII detection in the northeast regions was marginal. The surface brightnesses of the O-VIII line in 10(-7) photons cm(-2) s(-1) arcmin(-2) for the 2.2-3.3 and 3.3-4.4 Mpc regions were measured to be 2.7 +/- 1.0 and 2.1 +/- 1.2, giving upper limits on the baryon overdensity of delta = 319(< 442) and 284(< 446), respectively. This is comparable with previous observations of cluster outskirts and their theoretical predictions. The future prospect for WHIM detection using the Athena X-IFU micro-calorimeter is briefly discussed here. In addition, we also derived the intracluster medium temperature distribution of A 2744 to detect a clear discontinuity at the location of the radio relic. This suggests that the cluster has undergone strong shock heating by mass accretion along the filament., 2017年06月, 69, 3, id.39, 研究論文（学術雑誌）, 10.1093/pasj/psx011

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• 査読無し, 英語, NATURE, The quiescent intracluster medium in the core of the Perseus cluster, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall Bautz; Roger Blandford; Laura Brenneman; Gregory V. Brown; Esra Bulbul; Edward Cackett; Maria Chernyakova; Meng Chiao; Paolo Coppi; Elisa Costantini; Jelle de Plaa; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko Hiraga; Ann Hornschemeier; Akio Hoshino; John Hughes; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masayuki Itoh; Naoko Iyomoto; Jelle Kaastra; Timothy Kallman; Tuneyoshi Kamae; Erin Kara; Jun Kataoka; Satoru Katsuda; Junichiro Katsuta; Madoka Kawaharada; Nobuyuki Kawai; Richard Kelley; Dmitry Khangulyan; Caroline Kilbourne; Ashley King; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Shu Koyama; Katsuji Koyama; Peter Kretschmar; Hans Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Francois Lebrun; Shiu-Hang Lee; Maurice Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Grzegorz Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian McNamara; Missagh Mehdipour; Eric Miller; Jon Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Harvey Moseley; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky; Ryo Nagino; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Toshio Nakano; Shinya Nakashima; Kazuhiro Nakazawa; Masayoshi Nobukawa; Hirofumi Noda; Masaharu Nomachi; Steve O'Dell; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Arvind Parmar; Robert Petre; Ciro Pinto; Martin Pohl; F. Scott Porter; Katja Pottschmidt; Brian Ramsey; Christopher Reynolds; Helen Russell; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Hiroaki Sameshima; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Keisuke Tamura; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki Tanaka; Makoto Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shiro Ueno; Shin'ichiro Uno; Meg Urry; Eugenio Ursino; Cor De Vries; Shin Watanabe; Norbert Werner; Daniel Wik; Dan Wilkins; Brian Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Atsumasa Yoshida; Takayuki Yuasa; Irina Zhuravleva; Abderahmen Zoghbi, Clusters of galaxies are the most massive gravitationally bound objects in the Universe and are still forming. They are thus important probes(1) of cosmological parameters and many astrophysical processes. However, knowledge of the dynamics of the pervasive hot gas, the mass of which is much larger than the combined mass of all the stars in the cluster, is lacking. Such knowledge would enable insights into the injection of mechanical energy by the central supermassive black hole and the use of hydrostatic equilibrium for determining cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50-million-kelvin diffuse hot plasma filling its gravitational potential well. The active galactic nucleus of the central galaxy NGC 1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These bubbles probably induce motions in the intracluster medium and heat the inner gas, preventing runaway radiative cooling-a process known as active galactic nucleus feedback(2-6). Here we report X-ray observations of the core of the Perseus cluster, which reveal a remarkably quiescent atmosphere in which the gas has a line-of-sight velocity dispersion of 164 +/- 10 kilometres per second in the region 30-60 kiloparsecs from the central nucleus. A gradient in the line-of-sight velocity of 150 +/- 70 kilometres per second is found across the 60-kiloparsec image of the cluster core. Turbulent pressure support in the gas is four per cent of the thermodynamic pressure, with large-scale shear at most doubling this estimate. We infer that a total cluster mass determined from hydrostatic equilibrium in a central region would require little correction for turbulent pressure., 2016年07月, 535, 7610, 117, +, 研究論文（学術雑誌）, 10.1038/nature18627

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• 査読あり, 英語, ASTRONOMY & ASTROPHYSICS, Suzaku study of gas properties along filaments of A2744, Y. Ibaraki; N. Ota; H. Akamatsu; Y. -Y. Zhang; A. Finoguenov, Context. We present the results of Suzaku observations of a massive galaxy cluster A2744, which is an active merger at z = 0.308. Aims. By using long X-ray observations of A2744, we aim to understand the growth of the cluster and the gas heating process through mass accretion along the surrounding filaments. Methods. We analyzed data from two-pointed Suzaku observations of A2744 to derive the temperature distribution out to the virial radius in three different directions. We also performed a deprojection analysis to study radial profiles of gas temperature, density, and entropy and compared the X-ray results with multiwavelength data to investigate correlations with the surface density of galaxies and with radio relics. Results. The gas temperature was measured out to the virial radius r(200) in the north-eastern region and to about 1.5r(200) in the northwestern and southern regions. The radial profile of the gas temperature is rather flat and the temperature is very high (even near r(200)), which makes it comparable to the mean temperature of this cluster (kT = 9 keV). These characteristics have not been reported in any other cluster. We find a hint of temperature jump in the north-eastern region whose location coincides with a large radio relic, indicating that the cluster experienced gas heating because of merger or mass accretion onto the main cluster. The temperature distribution is anisotropic and shows no clear positive correlation with the galaxy density, which suggests an inhomogeneous mass structure and a complex merger history in A2744., 2014年02月, 562, id. A11, 6pp, 研究論文（学術雑誌）, 10.1051/0004-6361/201322806

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, X-ray properties of high-richness CAMIRA clusters in the Hyper Suprime-Cam Subaru Strategic Program field, Naomi Ota; Ikuyuki Mitsuishi; Yasunori Babazaki; Hiroki Akamatsu; Yuto Ichinohe; Shutaro Ueda; Nobuhiro Okabe; Masamune Oguri; Ryuichi Fujimoto; Takashi Hamana; Keita Miyaoka; Satoshi Miyazaki; Hanae Otani; Keigo Tanaka; Ayumi Tsuji; Atsushi Yoshida, We present the first results of a pilot X-ray study of 37 rich galaxy clusters at 0.1 < z < 1.1 in the Hyper Suprime-Cam Subaru Strategic Program field. Diffuse X-ray emissions from these clusters were serendipitously detected in the XMM-Newton fields of view. We systematically analyze X-ray images of 37 clusters and emission spectra of a subsample of 17 clusters with high photon statistics by using the XMM-Newton archive data. The frequency distribution of the offset between the X-ray centroid or peak and the position of the brightest cluster galaxy was derived for the optical cluster sample. The fraction of relaxed clusters estimated from the X-ray peak offsets in 17 clusters is 29 +/- 11(+/- 13)%, which is smaller than that of the X-ray cluster samples such as HIFLUGCS. Since the optical cluster search is immune to the physical state of X-ray-emitting gas, it is likely to cover a larger range of the cluster morphology. We also derive the luminosity-temperature relation and found that the slope is marginally shallower than those of X-ray-selected samples and consistent with the self-similar model prediction of 2. Accordingly, our results show that the X-ray properties of the optical clusters are marginally different from those observed in the X-ray samples. The implication of the results and future prospects are briefly discussed., 2020年02月, 72, 1, 研究論文（学術雑誌）, 10.1093/pasj/psz118

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• 英語, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, X-ray study of the double source plane gravitational lens system Eye of Horus observed with XMM-Newton, Keigo Tanaka; Ayumi Tsuji; Hiroki Akamatsu; J. H. H. Chan; Jean Coupon; Eiichi Egami; Francois Finet; Ryuichi Fujimoto; Yuto Ichinohe; Anton T. Jaelani; Chien-Hsiu Lee; Ikuyuki Mitsuishi; Anupreeta More; Surhud More; Masamune Oguri; Nobuhiro Okabe; Naomi Ota; Cristian E. Rusu; Alessandro Sonnenfeld; Masayuki Tanaka; Shutaro Ueda; Kenneth C. Wong, A double source plane (DSP) system is a precious probe for the density profile of distant galaxies and cosmological parameters. However, these measurements could be affected by the surrounding environment of the lens galaxy. Thus, it is important to evaluate the cluster-scale mass for detailed mass modelling. We observed the Eye of Horus, a DSP system discovered by the Hyper Suprime-Cam Subaru Strategic Survey (HSC-SSP), with XMM-Newton. We detected two X-ray extended emissions, originating from two clusters, one centred at the Eye of Horus, and the other located similar to 100 arcsec north-east to the Eye of Horus. We determined the dynamical mass assuming hydrostatic equilibrium, and evaluated their contributions to the lens mass interior of the Einstein radius. The contribution of the former cluster is 1.1(-0.5)(+1.2) x 10(12) M-circle dot, which is 21-76 per cent of the total mass within the Einstein radius. The discrepancy is likely due to the complex gravitational structure along the line of sight. On the other hand, the contribution of the latter cluster is only similar to 2 per cent on the Eye of Horus. Therefore, the influence associated with this cluster can be ignored., 2020年01月, 491, 3, 3411, 3418, 研究論文（学術雑誌）, 10.1093/mnras/stz3188

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Detection of polarized gamma-ray emission from the Crab nebula with the Hitomi Soft Gamma-ray Detector, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory V. Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Yuusuke Uchida, We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrometer, is capable of measuring polarization of gamma-ray photons. The Crab nebula is one of the brightest X-ray / gamma-ray sources on the sky, and, the only source from which polarized X-ray photons have been detected. SGD observed the Crab nebula during the initial test observation phase of Hitomi. We performed the data analysis of the SGD observation, the SGD background estimation and the SGD Monte Carlo simulations, and, successfully detected polarized gamma-ray emission from the Crab nebula with only about 5 ks exposure time. The obtained polarization fraction of the phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1% +/- 10.6%), and, the polarization angle is 110.degrees 7 + 13.degrees 2 /-13.degrees 0 in the energy range of 60-160 keV (The errors correspond to the 1 sigma deviation). The confidence level of the polarization detection was 99.3%. The polarization angle measured by SGD is about one sigma deviation with the projected spin axis of the pulsar, 124.degrees 0 +/- 0.degrees 1., 2018年12月, 70, 6, 研究論文（学術雑誌）, 10.1093/pasj/psy118

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, High entropy and evidence for a merger in the low surface brightness cluster Abell 2399, Ikuyuki Mitsuishi; Yasunori Babazaki; Naomi Ota; Shin Sasaki; Hans Boehringer; Gayoung Chon; Gabriel W. Pratt, We present results of the X-ray analyses of the nearby cluster of galaxies Abell 2399 (z = 0.058) using the XMM-Newton and Suzaku satellites. This cluster is classified as a low surface brightness (LSB) cluster. It has a bimodal structure in X-rays, and the X-ray-emission peaks are significantly offset from the peaks in gas temperature. By de-projecting the annular spectra, the temperature and electron density in the central r < 0.1 r(200) region are measured to be 3.6 keV and 1.4 x 10(-3) cm(-3), respectively. This yields a very high gas entropy, similar to 300 keV cm(2), in the central region, comparable to the values observed in other LSB clusters. The scaled entropy of Abell 2399 is the highest among the REXCESS cluster sample. The spatial distribution of the member galaxies exhibits multiple substructures, the locations of which are significantly different from those in the X-ray image. We discovered a clear discontinuity in the X-ray brightness and temperature distributions in the western gas clump, which provides evidence of the presence of a cold front. Therefore, our results strongly suggest that A2399 has experienced a merger and that the high central entropy originates from the merger activity., 2018年12月, 70, 6, 研究論文（学術雑誌）, 10.1093/pasj/psy117

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• 英語, ASTRONOMY & ASTROPHYSICS, Discovery of large scale shock fronts correlated with the radio halo and radio relic in the A2163 galaxy cluster, Sophia Thoelken; Thomas H. Reiprich; Martin W. Sommer; Naomi Ota, Context. Galaxy clusters form at the intersections of the filamentary large scale structure in merging events and by the accretion of matter along these filaments. Imprints of these formation processes should be visible in the intracluster medium and can arise in shock fronts, which are detectable via discontinuities in, for example, the gas temperature and density profiles. However, relatively few observational examples of prominent shocks have been detected in X-rays so far.Aims. In this study, we investigate the X-ray properties of the intracluster gas and the radio morphology of the extraordinary cluster A2163. This cluster shows an irregular morphology in various wavelengths and has one of the most luminous and extended radio halos known. Additionally, it is one of the hottest clusters known. We aim to measure the temperature and density profiles in two azimuthal directions to search for the presence of shock fronts.Methods. We performed a spectral analysis of data from two Suzaku observations, one in the north-east (NE) and one in the southwest (SW) direction of A2163, and used archival XMM-Newton data to remove point sources in the field of view. We deprojected the temperature and density profiles and accounted for the Suzaku point spread function. From the detected discontinuities in the density and temperature profiles, we estimated the Mach numbers and velocities of the shock fronts. To compare our findings in the X-ray regime with the radio emission, we obtained radio images of the cluster from an archival Very Large Array (VLA) observation at 20 cm.Results. We identify three shock fronts in A2163 in our spectral X-ray study. A clear shock front lies in the NE direction at a distance of 1.4 Mpc from the center, with a Mach number of M = 1.7(-0.2)(+0.3), estimated from the temperature discontinuity. This shock coincides with the position of a known radio relic. We identify two additional shocks in the SW direction, one with M = 1 .5(-0.3) (+0.5) at a distance of 0.7 Mpc, which is likely related to a cool core remnant, and a strong shock with M = 3.2-(+0.6)(0.7) at a distance of 1.3 Mpc, which also closely matches the radio contours. The complex structure of A2163 as well as the different Mach numbers and shock velocities suggest a merging scenario with two unequal merging constituents, where two shock fronts emerged at an early stage of the merger and traveled outwards while an additional shock front developed in front of the merging cluster cores., 2018年11月, 619, 研究論文（学術雑誌）, 10.1051/0004-6361/201834053

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• 英語, ASTROPHYSICAL JOURNAL, A Cool Core Disturbed: Observational Evidence for the Coexistence of Subsonic Sloshing Gas and Stripped Shock-heated Gas around the Core of RX J1347.5-1145, Shutaro Ueda; Tetsu Kitayama; Masamune Oguri; Eiichiro Komatsu; Takuya Akahori; Daisuke Iono; Takumi Izumi; Ryohei Kawabe; Kotaro Kohno; Hiroshi Matsuo; Naomi Ota; Yasushi Suto; Shigehisa Takakuwa; Motokazu Takizawa; Takahiro Tsutsumi; Kohji Yoshikawa, RX J1347.5-1145 (z = 0.451) is one of the most luminous X-ray galaxy clusters; it hosts a prominent cool core and exhibits a signature of a major merger. We present the first direct observational evidence for the subsonic nature of the sloshing motion of the cool core. We find that a residual X-ray image from the Chandra X-ray Observatory after removing the global emission shows a clear dipolar pattern characteristic of gas sloshing, whereas we find no significant residual in the Sunyaev-Zel'dovich effect (SZE) image from the Atacama Large Millimeter/submillimeter Array (ALMA). We estimate the equation of state of perturbations in the gas from the X-ray and SZE residual images. The inferred velocity is 420(-420)(+310) km s(-1), which is much lower than the adiabatic sound speed of the intracluster medium in the core. We thus conclude that the perturbation is nearly isobaric, and the gas sloshing motion is consistent with being in pressure equilibrium. Next, we report evidence for gas stripping of an infalling subcluster, which likely shock-heats the gas to a temperature well in excess of 20 keV. Using the mass distribution inferred from strong lensing images of the Hubble Space Telescope (HST), we find that the mass peak is located away from the peak position of the stripped gas with a statistical significance of >5 sigma. Unlike for the gas sloshing, the velocity inferred from the equation of state of the excess hot gas is comparable to the adiabatic sound speed expected for the 20 keV intracluster medium. All of the results support that the southeast substructure is created by a merger. On the other hand, the positional offset between the mass and the gas limits the self-interaction cross section of dark matter to be less than 3.7 h(-1) cm(2) g(-1) (95% CL)., 2018年10月, 866, 1, 研究論文（学術雑誌）, 10.3847/1538-4357/aadd9d

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Hitomi X-ray observation of the pulsar wind nebula G21.5-0.9, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Shinichiro Uno; Yoshihiro Ueda; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Toshiki Sato; Nozomu Nakaniwa; Hiroaki Murakami; Benson Guest, We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.5-0.9, whose emission is dominated by the pulsar wind nebula (PWN) contribution. The X-ray spectra in the 0.8-80 keV range obtained with the Soft X-ray Spectrometer (SXS), Soft X-ray Imager, and Hard X-ray Imager (HXI) show a significant break in the continuum as previously found with the NuSTAR observation. After taking into account all known emissions from the SNR other than the PWN itself, we find that the Hitomi spectra can be fitted with a broken power law with photon indices of Gamma(1) = 1.74 +/- 0.02 and Gamma(2) = 2.14 +/- 0.01 below and above the break at 7.1 +/- 0.3 keV, which is significantly lower than the NuSTAR result (similar to 9.0 keV). The spectral break cannot be reproduced by time-dependent particle injection one-zone spectral energy distribution models, which strongly indicates that a more complex emission model is needed, as suggested by recent theoretical models. We also search for narrow emission or absorption lines with the SXS, and perform a timing analysis of PSR J1833-1034 with the HXI and the Soft Gamma-ray Detector. No significant pulsation is found from the pulsar. However, unexpectedly, narrow absorption line features are detected in the SXS data at 4.2345 keV and 9.296 keV with a significance of 3.65 sigma. While the origin of these features is not understood, their mere detection opens up a new field of research and was only possible with the high resolution, sensitivity, and ability to measure extended sources provided by an X-ray microcalorimeter., 2018年06月, 70, 3, 研究論文（学術雑誌）, 10.1093/pasj/psy027

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Suzaku observations of low surface brightness cluster Abell 1631, Yasunori Babazak; Ikuyuki Mitsuishi; Naomi Ota; Shin Sasaki; Hans Boehringer; Gayoung Chon; Gabriel W. Pratt; Hironori Matsumoto, We present analysis results for a nearby galaxy cluster Abell 1631 at z = 0.046 using the X-ray observatory Suzaku. This cluster is categorized as a low X-ray surface brightness cluster. To study the dynamical state of the cluster, we conduct four-pointed Suzaku observations and investigate physical properties of the Mpc-scale hot gas associated with the A 1631 cluster for the first time. Unlike relaxed clusters, the X-ray image shows no strong peak at the center and an irregular morphology. We perform spectral analysis and investigate the radial profiles of the gas temperature, density, and entropy out to approximately 1.5 Mpc in the east, north, west, and south directions by combining with the XMM-Newton data archive. The measured gas density in the central region is relatively low (a few x 10(-4) cm(-3)) at the given temperature (similar to 2.9 keV) compared with X-ray-selected clusters. The entropy profile and value within the central region (r < 0.1 r(200)) are found to be flatter and higher (greater than or similar to 400 keV cm(2)). The observed bolometric luminosity is approximately three times lower than that expected from the luminosity-temperature relation in previous studies of relaxed clusters. These features are also observed in another low surface brightness cluster, Abell 76. The spatial distributions of galaxies and the hot gas appear to be different. The X-ray luminosity is relatively lower than that expected from the velocity dispersion. A post-merger scenario may explain the observed results., 2018年06月, 70, 3, 研究論文（学術雑誌）, 10.1093/pasj/psy036

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Suzaku Observations of Low Surface Brightness Cluster Abell 1631 (vol 70, 2018), Yasunori Babazaki; Ikuyuki Mitsuishi; Naomi Ota; Shin Sasaki; Hans Boehringer; Gayoung Chon; Gabriel W. Pratt; Hironori Matsumoto, 2018年06月, 70, 3, 10.1093/pasj/psy063

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Constraining hydrostatic mass bias of galaxy clusters with high-resolution X-ray spectroscopy, Naomi Ota; Daisuke Nagai; Erwin T. Lau, Gas motions in galaxy clusters play important roles in determining the properties of the intracluster medium (ICM) and in the constraint of cosmological parameters via X-ray and Sunyaev-Zel'dovich effect observations of galaxy clusters. The Hitomi measurements of gas motions in the core of the Perseus Cluster have provided new insights into the physics in galaxy clusters. The XARM mission, equipped with the Resolve X-ray micro-calorimeter, will continue Hitomi's legacy by measuring ICM motions through Doppler shifting and broadening of emission lines in a larger number of galaxy clusters, and at larger radii. In this work, we investigate how well we can measure bulk and turbulent gas motions in the ICM with XARM, by analyzing mock XARM simulations of galaxy clusters extracted from cosmological hydrodynamic simulations. We assess how photon counts, spectral fitting methods, multiphase ICM structure, deprojections, and region selection affect the measurements of gas motions. We first show that XARM is capable of recovering the underlying spherically averaged turbulent and bulk velocity profiles for dynamically relaxed clusters to within similar to 50% with a reasonable amount of photon counts in the X-ray emission lines. We also find that there are considerable azimuthal variations in the ICM velocities, where the velocities measured in a single azimuthal direction can significantly deviate from the true value even in dynamically relaxed systems. Such variation must be taken into account when interpreting data and developing observing strategies. We will discuss the prospect of using the upcoming XARM mission to measure non-thermal pressure and to correct for the hydrostatic mass bias of galaxy clusters. Our results are broadly applicable for future X-ray missions, such as Athena and Lynx., 2018年06月, 70, 3, 研究論文（学術雑誌）, 10.1093/pasj/psy040

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Hitomi observation of radio galaxy NGC 1275: The first X-ray microcalorimeter spectroscopy of Fe-K alpha line emission from an active galactic nucleus, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Taiki Kawamuro, The origin of the narrow Fe-K alpha fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the broad line region, a molecular torus, or interstellar/intracluster media. In 2016 February-March, we performed the first X-ray microcalorimeter spectroscopy with the Soft X-ray Spectrometer (SXS) on board the Hitomi satellite of the Fanaroff-Riley type I radio galaxy NGC 1275 at the center of the Perseus cluster of galaxies. With the high-energy resolution of similar to 5 eV at 6 keV achieved by Hitomi/SXS, we detected the Fe-K alpha line with similar to 5.4 sigma significance. The velocity width is constrained to be 500-1600 km s(-1) (FWHM for Gaussian models) at 90% confidence. The SXS also constrains the continuum level from the NGC 1275 nucleus up to similar to 20 keV, giving an equivalent width of similar to 20 eV for the 6.4 keV line. Because the velocity width is narrower than that of the broad H alpha line of similar to 2750 km s(-1), we can exclude a large contribution to the line flux from the accretion disk and the broad line region. Furthermore, we performed pixel map analyses on the Hitomi/SXS data and image analyses on the Chandra archival data, and revealed that the Fe-K alpha line comes from a region within similar to 1.6 kpc of the NGC 1275 core, where an active galactic nucleus emission dominates, rather than that from intracluster media. Therefore, we suggest that the source of the Fe-K alpha line from NGC 1275 is likely a low-covering-fraction molecular torus or a rotating molecular disk which probably extends from a parsec to hundreds of parsecs scale in the active galactic nucleus system., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx147

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Search for thermal X-ray features from the Crab nebula with the Hitomi soft X-ray spectrometer, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguch; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Toshiki Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemtsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Nozomu Tominaga; Takashi J. Moriya, The Crab nebula originated from a core-collapse supernova (SN) explosion observed in 1054 AD. When viewed as a supernova remnant (SNR), it has an anomalously low observed ejecta mass and kinetic energy for an Fe-core-collapse SN. Intensive searches have been made for a massive shell that solves this discrepancy, but none has been detected. An alternative idea is that SN 1054 is an electron-capture (EC) explosion with a lower explosion energy by an order of magnitude than Fe-core-collapse SNe. X-ray imaging searches were performed for the plasma emission from the shell in the Crab outskirts to set a stringent upper limit on the X-ray emitting mass. However, the extreme brightness of the source hampers access to its vicinity. We thus employed spectroscopic technique using the X-ray micro-calorimeter on board the Hitomi satellite. By exploiting its superb energy resolution, we set an upper limit for emission or absorption features from as yet undetected thermal plasma in the 2-12 keV range. We also re-evaluated the existing Chandra and XMM-Newton data. By assembling these results, a new upper limit was obtained for the X-ray plasma mass of less than or similar to 1 M-circle dot for a wide range of assumed shell radius, size, and plasma temperature values both in and out of collisional equilibrium. To compare with the observation, we further performed hydrodynamic simulations of the Crab SNR for two SN models (Fe-core versus EC) under two SN environments (uniform interstellar medium versus progenitor wind). We found that the observed mass limit can be compatible with both SN models if the SN environment has a low density of less than or similar to 0.03 cm(-3) (Fe core) or less than or similar to 0.1 cm(-3) (EC) for the uniform density, or a progenitor wind density somewhat less than that provided by amass loss rate of 10(-5) M-circle dot yr(-1) at 20 km s(-1) for the wind environment., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx072

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Glimpse of the highly obscured HMXB IGR J16318-4848 with Hitomi, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shinichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; Nozomi Nakaniwa, We report on a Hitomi observation of IGR J16318-4848, a high-mass X-ray binary system with an extremely strong absorption of N-H similar to 10(24) cm(-2). Previous X-ray studies revealed that its spectrum is dominated by strong fluorescence lines of Fe as well as continuum emission lines. For physical and geometrical insight into the nature of the reprocessing material, we utilized the high spectroscopic resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer: SXS) and the wide-band sensitivity by the soft and hard X-ray imagers (SXI and HXI) aboard Hitomi. Even though the photon counts are limited due to unintended off-axis pointing, the SXS spectrum resolves Fe K alpha(1) and K alpha(2) lines and puts strong constraints on the line centroid and line width. The line width corresponds to a velocity of 160(-70)(+300) km s(-1). This represents the most accurate, and smallest, width measurement of this line made so far from the any X-ray binary, much less than the Doppler broadening and Doppler shift expected from speeds that are characteristic of similar systems. Combined with the K-shell edge energy measured by the SXI and HXI spectra, the ionization state of Fe is estimated to be in the range of Fe I-IV. Considering the estimated ionization parameter and the distance between the X-ray source and the absorber, the density and thickness of the materials are estimated. The extraordinarily strong absorption and the absence of a Compton shoulder component have been confirmed. These characteristics suggest reprocessing materials that are distributed in a narrow solid angle or scattering, primarily by warm free electrons or neutral hydrogen. This measurement was achieved using the SXS detection of 19 photons. It provides strong motivation for follow-up observations of this and other X-ray binaries using the X-ray Astrophysics Recovery Mission and other comparable future instruments., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx154

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Atmospheric gas dynamics in the Perseus cluster observed with Hitomi, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Rebecca E. A. Canning; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Tasuku Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Shota Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumr; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Keigo Tanaka; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Qian H. S. Wang; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi, Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100 kpc of the Perseus cluster using observations obtained with the Hitomi satellite. After correcting for the point spread function of the telescope and using optically thin emission lines, we find that the line-of-sight velocity dispersion of the hot gas is remarkably low and mostly uniform. The velocity dispersion reaches a maxima of approximately 200 km s(-1) toward the central active galactic nucleus (AGN) and toward the AGN inflated northwestern "ghost" bubble. Elsewhere within the observed region, the velocity dispersion appears constant around 100 km s(-1). We also detect a velocity gradient with a 100 km s(-1) amplitude across the cluster core, consistent with large-scale sloshing of the core gas. If the observed gas motions are isotropic, the kinetic pressure support is less than 10% of the thermal pressure support in the cluster core. The well-resolved, optically thin emission lines have Gaussian shapes, indicating that the turbulent driving scale is likely below 100 kpc, which is consistent with the size of the AGN jet inflated bubbles. We also report the first measurement of the ion temperature in the intracluster medium, which we find to be consistent with the electron temperature. In addition, we present a new measurement of the redshift of the brightest cluster galaxy NGC 1275., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx138

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Measurements of resonant scattering in the Perseus Cluster core with Hitomi SXS, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Maki Furukawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Anna Ogorzalek; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shinichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi, Thanks to its high spectral resolution (similar to 5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us to measure the detailed structure of spatially resolved emission lines from highly ionized ions in galaxy clusters for the first time. In this series of papers, using the SXS we have measured the velocities of gas motions, metallicities and the multi-temperature structure of the gas in the core of the Perseus Cluster. Here, we show that when inferring physical properties from line emissivities in systems like Perseus, the resonant scattering effect should be taken into account. In the Hitomi waveband, resonant scattering mostly affects the Fe XXV He alpha line (w)-the strongest line in the spectrum. The flux measured by Hitomi in this line is suppressed by a factor of similar to 1.3 in the inner similar to 30 kpc, compared to predictions for an optically thin plasma; the suppression decreases with the distance from the center. The w line also appears slightly broader than other lines from the same ion. The observed distortions of the w line flux, shape, and distance dependence are all consistent with the expected effect of the resonant scattering in the Perseus core. By measuring the ratio of fluxes in optically thick (w) and thin (Fe XXV forbidden, He beta, Ly alpha) lines, and comparing these ratios with predictions from Monte Carlo radiative transfer simulations, the velocities of gas motions have been obtained. The results are consistent with the direct measurements of gas velocities from line broadening described elsewhere in this series, although the systematic and statistical uncertainties remain significant. Further improvements in the predictions of line emissivities in plasma models, and deeper observations with future X-ray missions offering similar or better capabilities to the Hitomi SXS, will enable resonant scattering measurements to provide powerful constraints on the amplitude and anisotropy of cluster gas motions., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx127

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Hitomi observations of the LMC SNR N 132 D: Highly redshifted X-ray emission from iron ejecta, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Toshiki Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi, We present Hitomi observations of N 132 D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at similar to 800 km s(-1) compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km s(-1) if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blueshifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of similar to 1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx151

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Temperature structure in the Perseus cluster core observed with Hitomi, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Maki Furukawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Yuichi Kato; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shinichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shinichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi, The present paper explains the temperature structure of X-ray emitting plasma in the core of the Perseus cluster based on 1.8-20.0 keV data obtained with the Soft X-ray Spectrometer (SXS) on board the Hitomi Observatory. A series of four observations was carried out, with a total effective exposure time of 338 ks that covered a central region of similar to 7' in diameter. SXS was operated with an energy resolution of similar to 5 eV (full width at half maximum) at 5.9 keV. Not only fine structures of K-shell lines in He-like ions, but also transitions from higher principal quantum numbers were clearly resolved from Si through Fe. That enabled us to perform temperature diagnostics using the line ratios of Si, S, Ar, Ca, and Fe, and to provide the first direct measurement of the excitation temperature and ionization temperature in the Perseus cluster. The observed spectrum is roughly reproduced by a single-temperature thermal plasma model in collisional ionization equilibrium, but detailed line-ratio diagnostics reveal slight deviations from this approximation. In particular, the data exhibit an apparent trend of increasing ionization temperature with the atomic mass, as well as small differences between the ionization and excitation temperatures for Fe, the only element for which both temperatures could be measured. The best-fit two-temperature models suggest a combination of 3 and 5 keV gas, which is consistent with the idea that the observed small deviations from a single-temperature approximation are due to the effects of projecting the known radial temperature gradient in the cluster core along the line of sight. A comparison with the Chandra/ACIS and the XMM-Newton/RGS results, on the other hand, suggests that additional lower-temperature components are present in the intracluster medium (ICM), but not detectable with Hitomi/SXS giving its 1.8-20 keV energy band., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psy004

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi, Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steven W. Allen; Lorella Angelini; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Aya Bamba; Marshall W. Bautz; Roger Blandford; Laura W. Brenneman; Gregory Brown; Esra Bulbul; Edward M. Cackett; Maria Chernyakova; Meng P. Chiao; Paolo S. Coppi; Elisa Costantini; Jelle de Plaa; Cor P. de Vries; Jan-Willem den Herder; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan E. Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew C. Fabian; Carlo Ferrigno; Adam R. Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi C. Gallo; Poshak Gandhi; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Ilana M. Harrus; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Natalie Hell; Junko S. Hiraga; Ann Hornschemeier; Akio Hoshino; John P. Hughes; Yuto Ichinohe; Ryo Iizuka; Hajime Inoue; Yoshiyuki Inoue; Manabu Ishida; Kumi Ishikawa; Yoshitaka Ishisaki; Masachika Iwai; Jelle Kaastra; Tim Kallman; Tsuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Nobuyuki Kawai; Richard L. Kelley; Caroline A. Kilbourne; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans A. Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Shiu-Hang Lee; Maurice A. Leutenegger; Olivier O. Limousin; Michael Loewenstein; Knox S. Long; David Lumb; Greg Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Brian R. McNamara; Missagh Mehdipour; Eric D. Miller; Jon M. Miller; Shin Mineshige; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Hideyuki Mori; Koji Mori; Koji Mukai; Hiroshi Murakami; Richard F. Mushotzky; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Kumiko K. Norukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Takaya Ohashi; Masanori Ohno; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Robert Petre; Ciro Pinto; Frederick S. Porter; Katja Pottschmidt; Christopher S. Reynolds; Samar Safi-Harb; Shinya Saito; Kazuhiro Sakai; Toru Sasaki; Goro Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter J. Serlemitsos; Hiromi Seta; Megumi Shidatsu; Aurora Simionescu; Randall K. Smith; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Tadayuki Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki T. Tanaka; Makoto S. Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Go Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Shutaro Ueda; Yoshihiro Ueda; Shin'ichiro Uno; C. Megan Urry; Eugenio Ursino; Shin Watanabe; Norbert Werner; Dan R. Wilkins; Brian J. Williams; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Y. Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Irina Zhuravleva; Abderahmen Zoghbi; A. J. J. Raassen, The Hitomi Soft X-ray Spectrometer spectrum of the Perseus cluster, with similar to 5 eV resolution in the 2-9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collisional plasmas. It reveals both successes and challenges of the current atomic data and models. The latest versions of AtomDB/APEC (3.0.8), SPEX (3.03.00), and CHIANTI (8.0) all provide reasonable fits to the broad-band spectrum, and are in close agreement on best-fit temperature, emission measure, and abundances of a few elements such as Ni. For the Fe abundance, the APEC and SPEX measurements differ by 16%, which is 17 times higher than the statistical uncertainty. This is mostly attributed to the differences in adopted collisional excitation and dielectronic recombination rates of the strongest emission lines. We further investigate and compare the sensitivity of the derived physical parameters to the astrophysical source modeling and instrumental effects. The Hitomi results show that accurate atomic data and models are as important as the astrophysical modeling and instrumental calibration aspects. Substantial updates of atomic databases and targeted laboratory measurements are needed to get the current data and models ready for the data from the next Hitomi-level mission., 2018年03月, 70, 2, 研究論文（学術雑誌）, 10.1093/pasj/psx156

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Multiwavelength study of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program S16A field, Keita Miyaoka; Nobuhiro Okabe; Takao Kitaguchi; Masamune Oguri; Yasushi Fukazawa; Rachel Mandelbaum; Elinor Medezinski; Yasunori Babazaki; Atsushi J. Nishizawa; Takashi Hamana; Yen-Ting Lin; Hiroki Akamatsu; I-Non Chiu; Yutaka Fujita; Yuto Ichinohe; Yutaka Komiyama; Toru Sasaki; Motokazu Takizawa; Shutaro Ueda; Keiichi Umetsu; Jean Coupon; Chiaki Hikage; Akio Hoshino; Alexie Leauthaud; Kyoko Matsushita; Ikuyuki Mitsuishi; Hironao Miyatake; Satoshi Miyazaki; Surhud More; Kazuhiro Nakazawa; Naomi Ota; Kousuke Sato; David Spergel; Takayuki Tamura; Masayuki Tanaka; Manobu M. Tanaka; Yousuke Utsumi, We present a joint X-ray, optical, and weak-lensing analysis for X-ray luminous galaxy clusters selected from the MCXC (Meta-Catalog of X-Ray Detected Clusters of Galaxies) cluster catalog in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey field with S16A data. As a pilot study for a series of papers, we measure hydrostatic equilibrium (HE) masses using XMM-Newton data for four clusters in the current coverage area out of a sample of 22 MCXC clusters. We additionally analyze a non-MCXC cluster associated with one MCXC cluster. We show that HE masses for the MCXC clusters are correlated with cluster richness from the CAMIRA catalog, while that for the non-MCXC cluster deviates from the scaling relation. The mass normalization of the relationship between cluster richness and HE mass is compatible with one inferred by matching CAMIRA cluster abundance with a theoretical halo mass function. The mean gas mass fraction based on HE masses for the MCXC clusters is < f(gas)> = 0.125 +/- 0.012 at spherical overdensity Delta = 500, which is similar to 80%-90% of the cosmic mean baryon fraction, Omega(b)/Omega(m), measured by cosmic microwave background experiments. We find that the mean baryon fraction estimated from X-ray and HSC-SSP optical data is comparable to Omega(b)/Omega(m). A weak-lensing shear catalog of background galaxies, combined with photometric redshifts, is currently available only for three clusters in our sample. Hydrostatic equilibrium masses roughly agree with weak-lensingmasses, albeit with large uncertainty. This study demonstrates that further multiwavelength study for a large sample of clusters using X-ray, HSC-SSP optical, and weak-lensing data will enable us to understand cluster physics and utilize cluster-based cosmology., 2018年01月, 70, 研究論文（学術雑誌）, 10.1093/pasj/psx132

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• 英語, SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY, Concept of X-ray Astronomy Recovery Mission, Makoto Tashiro; Hironori Maejima; Kenichi Toda; Richard Kelley; Lillian Reichenthal; James Lobell; Robert Petre; Matteo Guainazzi; Elisa Costantini; Mark Edison; Ryuichi Fujimoto; Martin Grim; Kiyoshi Hayashida; Jan-Willem den Herder; Yoshitaka Ishisaki; Stephane Paltani; Kyoko Matsushita; Koji Mori; Gary Sneiderman; Yoh Takei; Yukikatsu Terada; Hiroshi Tomida; Hiroki Akamatsu; Lorella Angelini; Yoshitaka Arai; Hisamitsu Awaki; Iurii Babyk; Aya Bamba; Peter Barfknecht; Kim Barnstable; Thomas Bialas; Branimir Blagojevic; Joseph Bonafede; Clifford Brambora; Laura Brenneman; Greg Brown; Kimberly Brown; Laura Burns; Edgar Canavan; Tim Carnahan; Meng Chiao; Brian Comber; Lia Corrales; Cor de Vries; Johannes Dercksen; Maria Diaz-Trigo; Tyrone Dillard; Michael DiPirro; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan Eckart; Teruaki Enoto; Yuichiro Ezoe; Carlo Ferrigno; Yutaka Fujita; Yasushi Fukazawa; Akihiro Furuzawa; Luigi Gallo; Steve Graham; Liyi Gu; Kohichi Hagino; Kenji Hamaguchi; Isamu Hatsukade; Dean Hawes; Takayuki Hayashi; Cailey Hegarty; Natalie Hell; Junko Hiraga; Edmund Hodges-Kluck; Matt Holland; Ann Hornschemeier; Akio Hoshino; Yuto Ichinohe; Ryo Iizuka; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Bryan James; Timothy Kallman; Erin Kara; Satoru Katsuda; Steven Kenyon; Caroline Kilbourne; Mark Kimball; Takao Kitaguchi; Shunji Kitamoto; Shogo Kobayashi; Takayoshi Kohmura; Shu Koyama; Aya Kubota; Maurice Leutenegger; Tom Lockard; Mike Loewenstein; Yoshitomo Maeda; Lynette Marbley; Maxim Markevitch; Connor Martz; Hironori Matsumoto; Keiichi Matsuzaki; Dan McCammon; Brian McNamara; Joseph Miko; Eric Miller; Jon Miller; Kenji Minesugi; Ikuyuki Mitsuishi; Tsunefumi Mizuno; Hideyuki Mori; Koji Mukai; Hiroshi Murakami; Richard Mushotzky; Hiroshi Nakajima; Hideto Nakamura; Shinya Nakashima; Kazuhiro Nakazawa; Chikara Natsukari; Kenichiro Nigo; Yusuke Nishioka; Kumiko Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Mina Ogawa; Takaya Ohashi; Masahiro Ohno; Masayuki Ohta; Takashi Okajima; Atsushi Okamoto; Michitaka Onizuka; Naomi Ota; Masanobu Ozaki; Paul Plucinsky; F. Scott Porter; Katja Pottschmidt; Kosuke Sato; Rie Sato; Makoto Sawada; Hiromi Seta; Ken Shelton; Yasuko Shibano; Maki Shida; Megumi Shidatsu; Peter Shirron; Aurora Simionescu; Randall Smith; Kazunori Someya; Yang Soong; Yasuharu Sugawara; Andy Szymkowiak; Hiromitsu Takahashi; Toru Tamagawa; Takayuki Tamura; Takaaki Tanaka; Yuichi Terashima; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yoshihiro Ueda; Shinichiro Uno; Thomas Walsh; Shin Watanabe; Brian Williams; Rob Wolfs; Michael Wright; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Yamasaki; Shigeo Yamauchi; Makoto Yamauchi; Keiichi Yanagase; Tahir Yaqoob; Susumu Yasuda; Nasa Yoshioka; Jaime Zabala; Irina Zhuravleva, The ASTRO-H mission was designed and developed through an international collaboration of JAXA, NASA, ESA, and the CSA. It was successfully launched on February 17, 2016, and then named Hitomi. During the in-orbit verification phase, the on-board observational instruments functioned as expected. The intricate coolant and refrigeration systems for soft X-ray spectrometer (SXS, a quantum micro-calorimeter) and soft X-ray imager (SXI, an X-ray CCD) also functioned as expected. However, on March 26, 2016, operations were prematurely terminated by a series of abnormal events and mishaps triggered by the attitude control system. These errors led to a fatal event: the loss of the solar panels on the Hitomi mission. The X-ray Astronomy Recovery Mission (or, XARM) is proposed to regain the key scientific advances anticipated by the international collaboration behind Hitomi. XARM will recover this science in the shortest time possible by focusing on one of the main science goals of Hitomi, "Resolving astrophysical problems by precise high-resolution X-ray spectroscopy".(1) This decision was reached after evaluating the performance of the instruments aboard Hitomi and the mission's initial scientific results, and considering the landscape of planned international X-ray astrophysics missions in 2020's and 2030's.Hitomi opened the door to high-resolution spectroscopy in the X-ray universe. It revealed a number of discrepancies between new observational results and prior theoretical predictions. Yet, the resolution pioneered by Hitomi is also the key to answering these and other fundamental questions. The high spectral resolution realized by XARM will not offer mere refinements; rather, it will enable qualitative leaps in astrophysics and plasma physics. XARM has therefore been given a broad scientific charge: "Revealing material circulation and energy transfer in cosmic plasmas and elucidating evolution of cosmic structures and objects". To fulfill this charge, four categories of science objectives that were defined for Hitomi will also be pursued by XARM; these include (1) Structure formation of the Universe and evolution of clusters of galaxies; (2) Circulation history of baryonic matters in the Universe; (3) Transport and circulation of energy in the Universe; (4) New science with unprecedented high resolution X-ray spectroscopy. In order to achieve these scientific objectives, XARM will carry a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and a wider field of view. This paper introduces the science objectives, mission concept, and observing plan of XARM., 2018年, 10699, 研究論文（国際会議プロシーディングス）, 10.1117/12.2309455

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Suzaku and Chandra observations of the galaxy cluster RXC J1053.7+5453 with a radio relic, Madoka Itahana; Motokazu Takizawa; Hiroki Akamatsu; Reinout J. van Weeren; Hajime Kawahara; Yasushi Fukazawa; Jelle S. Kaastra; Kazuhiro Nakazawa; Takaya Ohashi; Naomi Ota; Huub J. A. Rottgering; Jacco Vink; Fabio Zandanel, We present the results of Suzaku and Chandra observations of the galaxy cluster RXC J1053.7+5453 (z = 0.0704), which contains a radio relic. The radio relic is located at a distance of similar to 540 kpc from the X-ray peak toward the west. We measured the temperature of this cluster for the first time. The resultant temperature in the center is similar to 1.3 keV, which is lower than the value expected from the X-ray luminosity-temperature and the velocity dispersion-temperature relations. Though we did not find a significant temperature jump at the outer edge of the relic, our results suggest that the temperature decreases outward across the relic. Assuming the existence of the shock at the relic, its Mach number becomes M similar or equal to 1.4. A possible spatial variation of Mach number along the relic is suggested. Additionally, a sharp surface brightness edge is found at a distance of similar to 160 kpc from the X-ray peak toward the west in the Chandra image. We performed X-ray spectral and surface brightness analyses around the edge with the Suzaku and Chandra data, respectively. The obtained surface brightness and temperature profiles suggest that this edge is not a shock but likely a cold front. Alternatively, it cannot be ruled out that thermal pressure is really discontinuous across the edge. In this case, if the pressure across the surface brightness edge is in equilibrium, other forms of pressure sources, such as cosmic-rays, are necessary. We searched for the non-thermal inverse Compton component in the relic region. Assuming a photon index Gamma = 2.0, the resultant upper limit of the flux is 1.9 x 10(-14) erg s(-1) cm(-2) for a 4.50 x 10(-3) deg(2) area in the 0.3-10 keV band, which implies that the lower limit of magnetic field strength becomes 0.7 mu G., 2017年12月, 69, 6, 研究論文（学術雑誌）, 10.1093/pasj/psx095

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• 英語, ASTROPHYSICAL JOURNAL, Blind Millimeter Line Emitter Search using ALMA Data Toward Gravitational Lensing Clusters, Yuki Yamaguchi; Kotaro Kohno; Yoichi Tamura; Masamune Oguri; Hajime Ezawa; Natsuki H. Hayatsu; Tetsu Kitayama; Yuichi Matsuda; Hiroshi Matsuo; Tai Oshima; Naomi Ota; Takuma Izumi; Hideki Umehata, We present the results of a blind millimeter line emitter search using ALMA Band 6 data with a single-frequency tuning toward four gravitational lensing clusters (RXJ1347.5-1145, Abell S0592, MACS J0416.1-2403, and Abell 2744). We construct 3D signal-to-noise ratio (S/N) cubes with 60 and 100 MHz binning, and search for millimeter line emitters. We do not detect any line emitters with a peak S/N > 5, although we do find a line emitter candidate with a peak S/N similar or equal to 4.5. These results provide upper limits to the CO(3-2), CO(4-3), CO(5-4), and [C II] luminosity functions at z similar or equal to 0.3, 0.7, 1.2, and 6, respectively. Because of the magnification effect of gravitational lensing clusters, the new data provide the first constraints on the CO and [C II] luminosity functions at unprecedentedly low luminosity levels, i.e., down to less than or similar to 10(-3)-10(-1) Mpc(-3) dex(-1) at L'(CO) similar to 10(8)-10(10) Kkms(-1) pc(2) and less than or similar to 10(-3)-10(-2) Mpc(-3) dex(-1) at L[C II] similar to 10(8)-10(10) L-circle dot, respectively. Although the constraints to date are not yet stringent, we find that the evolution of the CO and [C II] luminosity functions are broadly consistent with the predictions of semi-analytical models. This study demonstrates that the wide observations with a single-frequency tuning toward gravitational lensing clusters are promising for constraining the CO and [C II] luminosity functions., 2017年08月, 845, 2, 研究論文（学術雑誌）, 10.3847/1538-4357/aa80e0

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, The Sunyaev-Zel'dovich effect at 5 '': RX J1347.5-1145 imaged by ALMA, Tetsu Kitayama; Shutaro Ueda; Shigehisa Takakuwa; Takahiro Tsutsumi; Eiichiro Komatsu; Takuya Akahori; Daisuke Iono; Takuma Izumi; Ryohei Kawabe; Kotaro Kohno; Hiroshi Matsuo; Naomi Ota; Yasushi Suto; Motozaku Takizawa; Kohji Yoshikawa, We present the first image of the thermal Sunyaev-Zel'dovich effect (SZE) obtained by the Atacama Large Millimeter/submillimeter Array (ALMA). Combining 7-m and 12-m arrays in Band 3, we create an SZE map toward a galaxy cluster RX J1347.5-1145 with 5 '' resolution (corresponding to a physical size of 20 h(-1) kpc), the highest angular and physical spatial resolutions achieved to-date for imaging the SZE, while retaining extended signals out to 40 '' . The 1 sigma statistical sensitivity of the image is 0.017 mJy beam(-1) or 0.12 mK(CMB) at the 5 '' full width at half maximum. The SZE image shows a good agreement with an electron pressure map reconstructed independently from the X-ray data and offers a new probe of the small-scale structure of the intracluster medium. Our results demonstrate that ALMA is a powerful instrument for imaging the SZE in compact galaxy clusters with unprecedented angular resolution and sensitivity. As the first report on the detection of the SZE by ALMA, we present detailed analysis procedures including corrections for the missing flux, to provide guiding methods for analyzing and interpreting future SZE images obtained by ALMA., 2016年10月, 68, 5, 研究論文（学術雑誌）, 10.1093/pasj/psw082

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• 英語, SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, The Astro-H High Resolution Soft X-Ray Spectrometer, Richard L. Kelley; Hiroki Akamatsu; Phillipp Azzarell; Tom Bialas; Kevin R. Boyce; Gregory V. Brown; Edgar Canavan; Meng P. Chiao; Elisa Costantini; Michael J. DiPirro; Megan E. Eckart; Yuichiro Ezoe; Ryuichi Fujimoto; Daniel Haas; Jan-Willem den Herder; Akio Hoshino; Kumi Ishikawa; Yoshitaka Ishisaki; Naoko Iyomoto; Caroline A. Kilbourne; Mark Kimball; Shunji Kitamoto; Saori Konami; Shu Koyama; Maurice A. Leutenegger; Dan McCammon; Joseph Miko; Kazuhisa Mitsuda; Ikuyuki Mitsuishi; Harvey Moseley; Hiroshi Murakami; Masahide Murakami; Hirofumi Noda; Mina Ogawa; Takaya Ohashi; Atsushi Okamoto; Naomi Ota; Stephane Paltani; F. Scott Porter; Kazuhiro Sakai; Kosuke Sato; Yohichi Sato; Makoto Sawada; Hiromi Seta; Keisuke Shinozaki; Peter J. Shirron; Gary A. Sneiderman; Hiroyuki Sugita; Andrew E. Szymkowiak; Yoh Takei; Toni Tamagawa; Makoto Tashiro; Yukikatsu Terada; Masahiro Tsujimoto; Cor P. de Vries; Shinya Yamada; Noriko Y. Yamasaki; Yoichi Yatsu, We present the overall design and performance of the Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array of x-ray microcalorimeters at the focus of a grazing-incidence x-ray mirror Soft X-Ray Telescope (SXT) for high-resolution spectroscopy of celestial x-ray sources. The instrument was designed to achieve an energy resolution better than 7 eV over the 0.3-12 keV energy range and operate for more than 3 years in orbit. The actual energy resolution of the instrument is 4-5 eV as demonstrated during extensive ground testing prior to launch and in orbit. The measured mass flow rate of the liquid helium cryogen and initial fill level at launch predict a lifetime of more than 4 years assuming steady mechanical cooler performance. Cryogen-free operation was successfully demonstrated prior to launch. The successful operation of the SXS in orbit, including the first observations of the velocity structure of the Perseus cluster of galaxies, demonstrates the viability and power of this technology as a tool for astrophysics., 2016年, 9905, 研究論文（国際会議プロシーディングス）, 10.1117/12.2232509

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• 英語, SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, The ASTRO-H (Hitomi) X-ray Astronomy Satellite, Tadayuki Takahashi; Motohide Kokubun; Kazuhisa Mitsuda; Richard Kelley; Takaya Ohashi; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steve Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Makoto Asai; Marc Audard; Hisamitsu Awaki; Magnus Axelsson; Philipp Azzarello; Chris Baluta; Aya Bamba; Nobutaka Bando; Marshall Bautz; Thomas Bialas; Roger Blandford; Kevin Boyce; Laura Brenneman; Greg Brown; Esra Bulbul; Edward Cackett; Edgar Canavan; Maria Chernyakova; Meng Chiao; Paolo Coppi; Elisa Costantini; Jelle de Plaa; Jan-Willem den Herder; Michael DiPirro; Chris Done; Tadayasu Dotani; John Doty; Ken Ebisawa; Megan Eckart; Teruaki Enoto; Yuichiro Ezoe; Andrew Fabian; Carlo Ferrigno; Adam Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi Gallo; Poshak Gandhi; Kirk Gilmore; Margherita Giustini; Andrea Goldwurm; Liyi Gu; Matteo Guainazzi; Daniel Haas; Yoshito Haba; Kouichi Hagino; Kenji Hamaguchi; Atsushi Harayama; Ilana Harrus; Isamu Hatsukade; Takayuki Hayashi; Katsuhiro Hayashi; Kiyoshi Hayashida; Junko Hiraga; Kazuyuki Hirose; Ann Hornschemeier; Akio Hoshino; John Hughes; Yuto Ichinohe; Ryo Iizuka; Yoshiyuki Inoue; Hajime Inoue; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Yoshitaka Ishisaki; Masayuki Itoh; Naoko Iwata; Naoko Iyomoto; Chris Jewell; Jelle Kaastra; Timothy Kallman; Tuneyoshi Kamae; Erin Kara; Jun Kataoka; Satoru Katsuda; Junichiro Katsuta; Madoka Kawaharada; Nobuyuki Kawai; Taro Kawano; Shigeo Kawasaki; Dmitry Khangulyan; Caroline Kilbourne; Mark Kimball; Ashley King; Takao Kitaguchi; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Tatsuro Kosaka; Alex Koujelev; Katsuji Koyama; Shu Koyama; Peter Kretschmar; Hans Krimm; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Francois Lebrun; Shiu-Hang Lee; Maurice Leutenegger; Olivier Limousin; Michael Loewenstein; Knox Long; David Lumb; Grzegorz Madejski; Yoshitomo Maeda; Daniel Maier; Kazuo Makishima; Maxim Markevitch; Candace Masters; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Daniel Mcguinness; Brian McNamara; Missagh Mehdipour; Joseph Miko; Jon Miller; Eric Miller; Shin Mineshige; Kenji Minesugi; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Koji Mori; Hideyuki Mori; Franco Moroso; Harvey Moseley; Theodore Muench; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky; Housei Nagano; Ryo Nagino; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Toshio Nakano; Shinya Nakashima; Kazuhiro Nakazawa; Yoshiharu Namba; Chikara Natsukari; Yusuke Nishioka; Masayoshi Nobukawa; Kumiko Nobukawa; Hirofumi Noda; Masaharu Nomachi; Steve O' Dell; Hirokazu Odaka; Hiroyuki Ogawa; Mina Ogawa; Keiji Ogi; Masanori Ohno; Masayuki Ohta; Takashi Okajima; Atsushi Okamoto; Tsuyoshi Okazaki; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Arvind Parmar; Robert Petre; Ciro Pinto; Martin Pohl; James Pontius; F. Scott Porter; Katja Pottschmidt; Brian Ramsey; Christopher Reynolds; Helen Russell; Samar Safi-Harb; Shinya Saito; Shin-ichiro Sakai; Kazuhiro Sakai; Hiroaki Sameshima; Toru Sasaki; Goro Sato; Yoichi Sato; Kosuke Sato; Rie Sato; Makoto Sawada; Norbert Schartel; Peter Serlemitsos; Hiromi Seta; Yasuko Shibano; Maki Shida; Megumi Shidatsu; Takanobu Shimada; Keisuke Shinozaki; Peter Shirron; Aurora Simionescu; Cynthia Simmons; Randall Smith; Gary Sneiderman; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Hiroyuki Sugita; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Shin'ichiro Takeda; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Keisuke Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki Tanaka; Makoto Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Yasunobu Uchiyama; Hideki Uchiyama; Yoshihiro Ueda; Shutaro Ueda; Shiro Ueno; Shin'ichiro Uno; Meg Urry; Eugenio Ursino; Cor de Vries; Atsushi Wada; Shin Watanabe; Tomomi Watanabe; Norbert Werner; Daniel Wik; Dan Wilkins; Brian Williams; Takahiro Yamada; Shinya Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Yoichi Yatsu; Daisuke Yonetoku; Atsumasa Yoshida; Takayuki Yuasa; Irina Zhuravleva; Abderahmen Zoghbi, The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. After a successful launch on 2016 February 17, the spacecraft lost its function on 2016 March 26, but the commissioning phase for about a month provided valuable information on the on-board instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month., 2016年, 9905, 研究論文（国際会議プロシーディングス）, 10.1117/12.2232379

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• 英語, SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, In-orbit operation of the ASTRO-H SXS, Masahiro Tsujimoto; Kazuhisa Mitsuda; Richard L. Kelley; Jan-Willem A. den Herder; Hiroki Akamatsu; Thomas G. Bialas; Kevin R. Boyce; Gregory V. Brown; Meng P. Chiao; Elisa Costantini; Cor P. de Vries; Michael J. DiPirro; Megan E. Eckart; Yuichiro Ezoe; Ryuichi Fujimoto; Daniel Haas; Akio Hoshino; Kumi Ishikawa; Yoshitaka Ishisaki; Naoko Iyomoto; Caroline A. Kilbourne; Shunji Kitamoto; Shu Koyama; Maurice A. Leutenegger; Dan McCammon; Ikuyuki Mitsuishi; Hiroshi Murakami; Masahide Murakami; Hirofumi Noda; Mina Ogawa; Naomi Ota; Stephane Paltani; Frederick S. Porter; Kosuke Sato; Yoichi Sato; Makoto Sawada; Hiromi Seta; Keisuke Shinozaki; Peter J. Shirron; Gary A. Sneiderman; Hiroyuki Sugita; Andrew E. Szymkowiak; Yoh Takei; Toru Tamagawa; Makoto S. Tashiro; Yukikatsu Terada; Shinya Yamada; Noriko Y. Yamasaki; Yoichi Yatsu, We summarize all the in-orbit operations of the Soft X-ray Spectrometer (SXS) onboard the ASTRO-H (Hitomi) satellite. The satellite was launched on 2016/02/17 and the communication with the satellite ceased on 2016/03/26. The SXS was still in the commissioning phase, in which the setups were progressively changed. This article is intended to serve as a reference of the events in the orbit to properly interpret the SXS data taken during its short life time, and as a test case for planning the in-orbit operation for future micro-calorimeter missions., 2016年, 9905, 研究論文（国際会議プロシーディングス）, 10.1117/12.2231784

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Universal profiles of the intracluster medium from Suzaku X-ray and Subaru weak-lensing observations, Nobuhiro Okabe; Keiichi Umetsu; Takayuki Tamura; Yutaka Fujita; Motokazu Takizawa; Yu-Ying Zhang; Kyoko Matsushita; Takashi Hamana; Yasushi Fukazawa; Toshifumi Futamase; Madoka Kawaharada; Satoshi Miyazaki; Yukiko Mochizuki; Kazuhiro Nakazawa; Takaya Ohashi; Naomi Ota; Toru Sasaki; Kosuke Sato; Sutieng Tam, We conduct a joint X-ray and weak-lensing study of four relaxed galaxy clusters (Hydra A, A 478, A1689, and A1835) observed by both Suzaku and Subaru out to virial radii, with the aim of understanding recently discovered unexpected features of the intracluster medium (ICM) in cluster outskirts. We show that the average hydrostatic-to-lensing total mass ratio for the four clusters decreases from similar to 70% to similar to 40% as the overdensity contrast decreases from 500 to the virial value. The average gas mass fraction from lensing total mass estimates increases with cluster radius and agrees with the cosmic mean baryon fraction within the virial radius, whereas the X-ray-based gas fraction considerably exceeds the cosmic values due to underestimation of the hydrostatic mass. We also develop a new advanced method for determining normalized cluster radial profiles for multiple X-ray observables by simultaneously taking into account both their radial dependence and multivariate scaling relations with weak-lensing masses. Although the four clusters span a range of halo mass, concentration, X-ray luminosity, and redshift, we find that the gas entropy, pressure, temperature, and density profiles are all remarkably self-similar when scaled with the weak-lensing M-200 mass and r(200) radius. The entropy monotonically increases out to similar to 0.5 r(200) similar to r(1000) following the accretion shock heating model K(r) proportional to r(1.1), and flattens at greater than or similar to 0.5 r(200). The universality of the scaled entropy profiles indicates that the thermalization mechanism over the entire cluster region (> 0.1 r(200)) is controlled by gravitation in a common way for all clusters, although the heating efficiency in the outskirts needs to be modified from the standard r(1.1) law. The bivariate scaling functions of the gas density and temperature reveal that the flattening of the outskirts entropy profile is caused by the steepening of the temperature, rather than the flattening of the gas density., 2014年10月, 66, 5, 研究論文（学術雑誌）, 10.1093/pasj/psu075

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Thermal and non-thermal X-rays from the Galactic supernova remnant G348.5+0.1, Shigeo Yamauchi; Sari Minami; Naomi Ota; Katsuji Koyama, We report on Suzaku results of the two distinct regions in the Galactic supernova remnant G348.5+0.1: extended thermal X-rays ("soft diffuse") at the north-east region and non-thermal X-rays (CXOU J171419.8-383023) at the north-west region. The X-ray spectrum of the soft diffuse X-rays can be fitted with neither an ionization equilibrium nor a non-equilibrium (ionizing) plasma model, leaving saw-tooth residuals in the 1.5-3 keV energy band. The residual structures can be produced when free electrons are recombined to the K-shells of highly ionized Mg and Si ions. In fact, the X-ray spectrum is nicely fitted with a recombination-dominant plasma model. We propose a scenario whereby the plasma in a nearly fully ionized state at high temperature quickly changed to a recombining phase due to selective cooling of electrons to a lower temperature of similar to 0.5 keV. The spectrum of CXOU J171419.8-383023 is well explained by a simple power-law model with a photon index of 1.9, nearly equal to the typical value for pulsar wind nebulae. Since the distance is estimated to be the same as that of the soft diffuse radiation, we infer that both the soft diffuse X-rays and CXOU J171419.8-383023 are associated with the same object, SNR G348.5+0.1., 2014年02月, 66, 1, 研究論文（学術雑誌）, 10.1093/pasj/pst004

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• 英語, SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, Soft x-ray spectrometer (SXS): the high-resolution cryogenic spectrometer onboard ASTRO-H, Kazuhisa Mitsuda; Richard L. Kelley; Hiroki Akamatsu; Thomas Bialas; Kevin R. Boyce; Gregory V. Brown; Edgar Canavan; Meng Chiao; Elisa Costantini; Jan-Willem den Herder; Cor de Vries; Michael J. DiPirro; Megan E. Eckart; Yuichiro Ezoe; Ryuichi Fujimoto; Daniel Haas; Akio Hoshino; Kumi Ishikawa; Yoshitaka Ishisaki; Naoko Iyomoto; Caroline A. Kilbourne; Mark Kimball; Shunji Kitamoto; Saori Konami; Maurice A. Leutenegger; Dan McCammon; Joseph Miko; Ikuyuki Mitsuishi; Hiroshi Murakami; Masahide Murakami; Hirofumi Noda; Mina Ogawa; Takaya Ohashi; Atsushi Okamoto; Naomi Ota; Stephane Paltani; F. Scott Porter; Kosuke Sato; Yoichi Sato; Makoto Sawada; Hitomi Seta; Keisuke Shinozaki; Peter J. Shirron; Gary A. Sneiderman; Hiroyuki Sugita; Andrew Szymkowiak; Yoh Takei; Toru Tamagawa; Makoto S. Tashiro; Yukikatsu Terada; Masahiro Tsujimoto; Shinya Yamada; Noriko Y. Yamasaki, We present the development status of the Soft X-ray Spectrometer (SXS) onboard the ASTRO-H mission. The SXS provides the capability of high energy-resolution X-ray spectroscopy of a FWHM energy resolution of < 7eV in the energy range of 0.3 - 10 keV. It utilizes an X-ray micorcalorimeter array operated at 50 mK. The SXS microcalorimeter subsystem is being developed in an EM-FM approach. The EM SXS cryostat was developed and fully tested and, although the design was generally confirmed, several anomalies and problems were found. Among them is the interference of the detector with the micro-vibrations from the mechanical coolers, which is the most difficult one to solve. We have pursued three different countermeasures and two of them seem to be effective. So far we have obtained energy resolutions satisfying the requirement with the FM cryostat., 2014年, 9144, 研究論文（国際会議プロシーディングス）, 10.1117/12.2057199

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• 英語, SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, The ASTRO-H X-ray Astronomy Satellite, Tadayuki Takahashi; Kazuhisa Mitsuda; Richard Kelley; Felix Aharonian; Hiroki Akamatsu; Fumie Akimoto; Steve Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Makoto Asai; Marc Audard; Hisamitsu Awaki; Philipp Azzarello; Chris Baluta; Aya Bamba; Nobutaka Bando; Marshall Bautz; Thomas Bialas; Roger Blandford; Kevin Boyce; Laura Brenneman; Greg Brown; Edward Cackett; Edgar Canavan; Maria Chernyakova; Meng Chiao; Paolo Coppi; Elisa Costantini; Jelle de Plaa; Jan-Willem den Herder; Michael DiPirro; Chris Done; Tadayasu Dotani; John Doty; Ken Ebisawa; Teruaki Enoto; Yuichiro Ezoe; Andrew Fabian; Carlo Ferrigno; Adam Foster; Ryuichi Fujimoto; Yasushi Fukazawa; Stefan Funk; Akihiro Furuzawa; Massimiliano Galeazzi; Luigi Gallo; Poshak Gandhi; Kirk Gilmore; Matteo Guainazzi; Daniel Haas; Yoshito Haba; Kenji Hamaguchi; Atsushi Harayama; Isamu Hatsukade; Katsuhiro Hayashi; Takayuki Hayashi; Kiyoshi Hayashida; Junko Hiraga; Kazuyuki Hirose; Ann Hornschemeier; Akio Hoshino; John Hughes; Una Hwang; Ryo Iizuka; Yoshiyuki Inoue; Kazunori Ishibashi; Manabu Ishida; Kumi Ishikawa; Kosei Ishimura; Yoshitaka Ishisaki; Masayuki Itoh; Naoko Iwata; Naoko Iyomoto; Chris Jewell; Jelle Kaastra; Timothy Kallman; Tuneyoshi Kamae; Jun Kataoka; Satoru Katsuda; Junichiro Katsuta; Madoka Kawaharada; Nobuyuki Kawai; Taro Kawano; Shigeo Kawasaki; Dmitry Khangaluyan; Caroline Kilbourne; Mark Kimball; Masashi Kimura; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Saori Konami; Tatsuro Kosaka; Alexander Koujelev; Katsuji Koyama; Hans Krimm; Aya Kubota; Hideyo Kunieda; Stephanie LaMassa; Philippe Laurent; Francois Lebrun; Maurice Leutenegger; Olivier Limousin; Michael Loewenstein; Knox Long; David Lumb; Grzegorz Madejski; Yoshitomo Maeda; Kazuo Makishima; Maxim Markevitch; Candace Masters; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Daniel McGuinness; Brian McNamara; Joseph Miko; Jon Miller; Eric Miller; Shin Mineshige; Kenji Minesugi; Ikuyuki Mitsuishi; Takuya Miyazawa; Tsunefumi Mizuno; Koji Mori; Hideyuki Mori; Franco Moroso; Theodore Muench; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky; Housei Nagano; Ryo Nagino; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Shinya Nakashima; Kazuhiro Nakazawa; Yoshiharu Namba; Chikara Natsukari; Yusuke Nishioka; Masayoshi Nobukawa; Hirofumi Noda; Masaharu Nomachi; Steve O' Dell; Hirokazu Odaka; Hiroyuki Ogawa; Mina Ogawa; Keiji Ogi; Takaya Ohashi; Masanori Ohno; Masayuki Ohta; Takashi Okajima; Tsuyoshi Okazaki; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Arvind Parmar; Robert Petre; Ciro Pinto; Martin Pohl; James Pontius; F. Scott Porter; Katja Pottschmidt; Brian Ramsey; Rubens Reis; Christopher Reynolds; Claudio Ricci; Helen Russell; Samar Safi-Harb; Shinya Saito; Shin-ichiro Sakai; Hiroaki Sameshima; Kosuke Sato; Rie Sato; Goro Sato; Makoto Sawada; Peter Serlemitsos; Hiromi Seta; Yasuko Shibano; Maki Shida; Takanobu Shimada; Peter Shirron; Aurora Simionescu; Cynthia Simmons; Randall Smith; Gary Sneiderman; Yang Soong; Lukasz Stawarz; Yasuharu Sugawara; Satoshi Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiroaki Takahashi; Hiromitsu Takahashi; Shin-ichiro Takeda; Yoh Takei; Toru Tamagawa; Keisuke Tamura; Takayuki Tamura; Takaaki Tanaka; Yasuyuki Tanaka; Yasuo Tanaka; Makoto Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Yoko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Hideki Uchiyama; Yasunobu Uchiyama; Yoshihiro Ueda; Shutaro Uedag; Shiro Ueno; Shinichiro Uno; Meg Urry; Eugenio Ursino; Cor de Vries; Atsushi Wada; Shin Watanabe; Tomomi Watanabe; Norbert Werner; Nicholas White; Dan Wilkins; Shinya Yamada; Takahiro Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yadoob; Yoichi Yatsu; Daisuke Yonetoku; Atsumasa Yoshida; Takayuki Yuasa; Irina Zhuravleva; Abderahmen Zoghbi; John ZuHone, The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of Delta E <= 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts., 2014年, 9144, 研究論文（国際会議プロシーディングス）, 10.1117/12.2055681

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• 査読無し, その他, ASTRO-H White Paper - Clusters of Galaxies and Related Science, OTA Naomi; Kitayama, T; Bautz, M; Markevitch, M; Matsushita, K; Allen, S; Kawaharada, M; McNamara, B; Ota, N; Akamatsu, H; de Plaa, J; Galeazzi, M; Madejski, G; Main, R; Miller, E; Nakazawa, K; Russell, H; Sato, K; Sekiya, N; Simionescu, A; Tamura, T; Uchida, Y; Ursino, E; Werner, N; Zhuravleva, I; ZuHone, J; on behalf of; the; ASTRO-H; Science Working Group, 2014年
• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, X-Ray Observation of the Galactic Supernova Remnant G355.6-0.0 with Suzaku, Sari Minami; Naomi Ota; Shigeo Yamauchi; Katsuji Koyama, We present results of the Galactic supernova remnant (SNR) G355.6-0.0 observed with Suzaku. We resolved diffuse emission detected with ASCA into two objects, G355.6-0.0 and a point-like source, Suzaku J173530-3236. The X-ray emission from G355.6-0.0 exhibits a center-filled morphology within the radio shell. The X-ray spectrum is well-represented by a thin thermal plasma model with enhanced metal abundances. The spatial and spectral properties imply that G355.6-0.0 is a member of the mixed-morphology SNRs. The N-H value of similar to 6 x 10(22) cm(-2) supports that G355.6-0.0 is a distant SNR. Suzaku J173530-3236 exhibits a hard X-ray spectrum with a strong Fe emission line, similar to those of cataclysmic variables. The N-H value of similar to 3 x 10(22) cm(-2) is smaller than that of G355.6-0.0, and hence Suzaku J173530-3236 is located at the near side of G355.6-0.0., 2013年10月, 65, 5, 研究論文（学術雑誌）, 10.1093/pasj/65.5.99

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• 英語, ASTROPHYSICAL JOURNAL, SUZAKU OBSERVATIONS OF THE OUTSKIRTS OF A1835: DEVIATION FROM HYDROSTATIC EQUILIBRIUM, Kazuya Ichikawa; Kyoko Matsushita; Nobuhiro Okabe; Kosuke Sato; Y. -Y. Zhang; A. Finoguenov; Yutaka Fujita; Yasushi Fukazawa; Madoka Kawaharada; Kazuhiro Nakazawa; Takaya Ohashi; Naomi Ota; Motokazu Takizawa; Takayuki Tamura; Keiichi Umetsu, We present results of four-pointing Suzaku X-ray observations (total similar to 200 ks) of the intracluster medium (ICM) in the A1835 galaxy cluster (kT similar to 8 keV, z = 0.253) out to the virial radius (r(vir) similar to 2.9 Mpc) and beyond. Faint X-ray emission from the ICM out to rvir is detected. The temperature gradually decreases with radius from similar to 8 keV in the inner region to similar to 2 keV at r(vir). The entropy profile is shown to flatten beyond r(500), in disagreement with the r(1.1) dependence predicted from the accretion shock heating model. The thermal pressure profile in the range 0.3r(500) less than or similar to r less than or similar to r(vir) agrees well with that obtained from the stacked Sunyaev-Zel'dovich effect observations with the Planck satellite. The hydrostatic mass profile in the cluster outskirts (r(500) less than or similar to r less than or similar to r(vir)) falls well short of the weak-lensing one derived from Subaru/Suprime-Cam observations, showing an unphysical decrease with radius. The gas mass fraction at r(vir) defined with the lensing total mass agrees with the cosmic baryon fraction from the Wilkinson Microwave Anisotropy Probe seven-year data. All these results indicate, rather than the gas-clumping effect, that the bulk of the ICM in the cluster outskirts is far from hydrostatic equilibrium and infalling matter retained some of its kinetic energy. Finally, combining with our recent Suzaku and lensing analysis of A1689, a cluster of similar mass, temperature, and redshift, we show that the cluster temperature distribution in the outskirts is significantly correlated with the galaxy density field in the surrounding large-scale environment at (1-2)r(vir)., 2013年04月, 766, 2, 研究論文（学術雑誌）, 10.1088/0004-637X/766/2/90

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Density Profile of a Cool Core of Galaxy Clusters, Naomi Ota; Kiyokazu Onzuka; Kuniaki Masai, The density profile of a cool core of intracluster gas is investigated for a cluster of galaxies that is initially in the virial equilibrium state, and then undergoes radiative cooling. The initial gas profile is derived under the assumption that the gas is hydrostatic within the dark-matter potential presented by the "NFW" or King model, and has a polytropic profile. The contribution of masses of gas and galaxies to the potential in the calculation is ignored compared to the dark matter. The temperature and density profiles of gas in its quasi-hydrostatic cooling phase, which is expected to last for similar to Gyr, are then calculated for different initial gas profiles. It is found that in the quasi-hydrostatic cooling phase, while the temperature decreases to about one-third, the density increases by a factor of 4-6 at the cluster center in comparison with its initial polytropic value, though the profiles over the core depend on the dark-matter potential. Hence, the core radius in the quasi-hydrostatic cooling gas appears to be smaller than that in the initial polytropic gas. We compared the density profile of the cool core with observations to find that, while the initial density is around the upper bounds of large-core (> 100 kpc) clusters, most likely relaxed, but the cooling is not yet significant, the central density under quasi-hydrostatic cooling falls between the mid- and high-values of small (<100 kpc)- or cool-core clusters. It is also found for the quasi-hydrostatic cooling gas that the entropy profile roughly agrees with the best-fit model to the ACCEPT cluster sample with a low central entropy; also, the pressure gradient in the core is close to that of the REXCESS sample. X-ray surface brightness calculated for the quasi-hydrostatic cooling gas is well represented by the conventional double beta-model, giving a physical basis for applying the double beta-model to cool-core clusters., 2013年04月, 65, 2, 研究論文（学術雑誌）, 10.1093/pasj/65.2.47

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• 英語, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, The Hidden Fortress: structure and substructure of the complex strong lensing cluster SDSS J1029+2623, Masamune Oguri; Tim Schrabback; Eric Jullo; Naomi Ota; Christopher S. Kochanek; Xinyu Dai; Eran O. Ofek; Gordon T. Richards; Roger D. Blandford; Emilio E. Falco; Janine Fohlmeister, We present Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3) observations of SDSS J1029+2623, a three-image quasar lens system produced by a foreground cluster at z = 0.584. Our strong lensing analysis reveals six additional multiply imaged galaxies in addition to the multiply imaged quasar. We confirm the complex nature of the mass distribution of the lensing cluster, with a bimodal dark matter distribution which deviates from the Chandra X-ray surface brightness distribution. The Einstein radius of the lensing cluster is estimated to be theta(E) = 15.2 +/- 0.5 arcsec for the quasar redshift of z = 2.197. We derive a radial mass distribution from the combination of strong lensing, HST/ACS weak lensing and Subaru/Suprime-cam weak lensing analysis results, finding a best-fitting virial mass of M-vir = 1.55(-0.35)(+0.40) x 10(14) h(-1) M-circle dot and a concentration parameter of c(vir) = 25.7(-7.5)(+14.1). The lensing mass estimate at the outer radius is smaller than the X-ray mass estimate by a factor of similar to 2. We ascribe this large mass discrepancy to shock heating of the intracluster gas during a merger, which is also suggested by the complex mass and gas distributions and the high value of the concentration parameter. In the HST image, we also identify a probable galaxy, GX, in the vicinity of the faintest quasar image C. In strong lens models, the inclusion of GX explains the anomalous flux ratios between the quasar images. The morphology of the highly elongated quasar host galaxy is also well reproduced. The best-fitting model suggests large total magnifications of 30 for the quasar and 35 for the quasar host galaxy, and has an AB time delay consistent with the measured value., 2013年02月, 429, 1, 482, 493, 研究論文（学術雑誌）, 10.1093/mnras/sts351

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• 英語, VETERINARY PARASITOLOGY, Expression and immunological characterization of the heat shock protein-70 homologue from Babesia bigemina, Mahmoud AbouLaila; Mohamad Alaa Terkawi; Faasoa Junior Seuseu; Naomi Ota; Alan Caine Costa de Macedo; Naoaki Yokoyama; Xuenan Xuan; Ikuo Igarashi, The Babesia bigemina heat shock protein-70 gene (BbigHSP-70) was cloned from cDNA by polymerase chain reaction (PCR) and sequenced. The length of the gene is 1947 bp and the predicted polypeptide is 649 amino acids long with a calculated molecular weight of 70.85 kDa. BbigHSP-70 has a signal peptide of 15 amino acids. Phylogenetic analysis of the amino acid sequence of BbigHSP-70 showed that B. bigemina was most closely related to B. caballi and B. bovis and lies within a phylogenetic cluster with Theileria. rBbigHSP-70 was expressed in E. colt as a soluble GST-fusion protein with a molecular mass of 96.8-kDa. The serum raised in mice against rBbigHSP-70 detected the native protein in B. bigemina, B. bovis, B. caballi, B. gibsoni, and B. microti lysates and also reacted with B. bigemina, B. bovis, and B. caballi merozoites in the IFAT. Mice vaccinated with rBbigHSP-70 showed lower parasitemia against the challenge infection with B. microti than GST-vaccinated and non-vaccinated controls. These results added a new member of Babesia heat shock proteins70 that is well conserved among intraerythrocytic protozoa and demonstrated its protective effects in an experimental model of rodent babesiosis. (C) 2012 Elsevier BM. All rights reserved., 2012年12月, 190, 3-4, 401, 410, 研究論文（学術雑誌）, 10.1016/j.vetpar.2012.06.035

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• 英語, ASTROPHYSICAL JOURNAL, THE CHANDRA VIEW OF THE LARGEST QUASAR LENS SDSS J1029+2623, Naomi Ota; Masamune Oguri; Xinyu Dai; Christopher S. Kochanek; Gordon T. Richards; Eran O. Ofek; Roger D. Blandford; Tim Schrabback; Naohisa Inada, We present results from Chandra observations of the cluster lens SDSS J1029+2623 at z(l) = 0.58, which is a gravitationally lensed quasar with the largest known image separation. We clearly detect X-ray emission both from the lensing cluster and the three lensed quasar images. The cluster has an X-ray temperature of kT = 8.1(-1.2)(+2.0) keV and bolometric luminosity of L-X = 9.6 x 10(44) erg s(-1). Its surface brightness is centered near one of the brightest cluster galaxies, and it is elongated east-west. We identify a subpeak northwest of the main peak, which is suggestive of an ongoing merger. Even so, the X-ray mass inferred from the hydrostatic equilibrium assumption appears to be consistent with the lensing mass from the Einstein radius of the system. We find significant absorption in the soft X-ray spectrum of the faintest quasar image, which can be caused by an intervening material at either the lens or source redshift. The X-ray flux ratios between the quasar images (after correcting for absorption) are in reasonable agreement with those at optical and radio wavelengths, and all the flux ratios are inconsistent with those predicted by simple mass models. This implies that microlensing effect is not significant for this system and dark matter substructure is mainly responsible for the anomalous flux ratios., 2012年10月, 758, 1, 研究論文（学術雑誌）, 10.1088/0004-637X/758/1/26

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• 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, Suzaku Observations of the Hydra A Cluster out to the Virial Radius, Takuya Sato; Toru Sasaki; Kyoko Matsushita; Eri Sakuma; Kosuke Sato; Yutaka Fujita; Nobuhiro Okabe; Yasushi Fukazawa; Kazuya Ichikawa; Madoka Kawaharada; Kazuhiro Nakazawa; Takaya Ohashi; Naomi Ota; Motokazu Takizawa; Takayuki Tamura, We report on Suzaku observations of the northern half of the Hydra A cluster out to similar to 1.4 Mpc, reaching the virial radius. There are the first Suzaku observations of a medium-size (k T similar to 3 keV) cluster out to the virial radius. Two observations were conducted, north-west and north-east offsets, which continue in a filament direction and a void direction of the large-scale structure of the Universe, respectively. The X-ray emission and distribution of galaxies elongate in the filament direction. The temperature profiles in the two directions are mostly consistent with each other within the error bars, and drop to 1.5 keV at 1.5 r(500). As observed by Suzaku in hot clusters, the entropy profile becomes flatter beyond r(500), in disagreement with the r(1.1) relationship, which is expected from accretion shock heating models. When scaled with the average intracluster medium (ICM) temperature, the entropy profiles of clusters observed with Suzaku are universal, and do not depend on the system mass. The hydrostatic mass values in the void and filament directions are in good agreement, and the Navarro, Frenk, and White universal mass profile represents the hydrostatic mass distribution up to similar to 2r(500). Beyond r(500), the ratio of the gas mass to the hydrostatic mass exceeds the result of the Wilkinson microwave anisotropy probe, and at r(100), these ratios in the filament and void directions reach 0.4 and 0.3, respectively. We discuss possible deviations from the hydrostatic equilibrium at cluster outskirts. We derived radial profiles of the gas-mass-to-light ratio and the iron-mass-to-light ratio out to the virial radius. Within r(500), the iron-mass-to-light ratio of the Hydra A cluster was compared with those in other clusters observed with Suzaku., 2012年10月, 64, 5, 研究論文（学術雑誌）, 10.1093/pasj/64.5.95

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• 査読無し, 英語, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, Thick and large area PIN diodes for hard X-ray astronomy, N Ota; T Murakami; M Sugizaki; H Kaneda; T Tamura; H Ozawa; T Kamae; K Makishima; T Takahashi; M Tashiro; Y Fukazawa; J Kataoka; K Yamaoka; S Kubo; C Tanihata; Y Uchiyama; K Matsuzaki; N Iyomoto; M Kokubun; T Nakazawa; A Kubota; T Mizuno; Y Matsumoto; N Isobe; Y Terada; M Sugiho; T Onishi; H Kubo; H Ikeda; M Nomachi; T Ohsugi; M Muramatsu; H Akahori, Thick and large area PIN diodes for the hard X-ray astronomy in the 10-60 keV range are developed. To cover this energy range in a room temperature and in a low background environment, Si PIN junction diodes of 2 mm in thickness with 2.5 cm(2) in effective area were developed, and will be used in the bottom of the Phoswich Hard X-ray Detector (HXD), on-board the ASTRO-E satellite. Problems related to a high purity Si and a thick depletion layer during our development and performance of the PIN diodes are presented in detail. (C) 1999 Elsevier Science B.V. All rights reserved., 1999年10月, 436, 1-2, 291, 296, 研究論文（学術雑誌）, 10.1016/S0168-9002(99)00636-1

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• 査読無し, 英語, HARD X-RAY AND GAMMA-RAY DETECTOR PHYSICS, OPTICS, AND APPLICATIONS, Development of the large area silicon PIN diode with 2 mm-thick depletion layer for hard x-ray detector (HXD) on-board ASTRO-E, M Sugizaki; S Kubo; T Murakami; N Ota; H Ozawa; T Takahashi; H Kaneda; N Iyomoto; T Kamae; M Kokubun; A Kubota; K Makishima; T Tamura; M Tashiro; K Koyama; H Tsunemi, ASTRO-E is the next Japanese X-ray satellite to be launched in the year of 2000, It carries three high-energy astrophysical experiments, including the Hard X-ray Detector (HXD) which is unique in covering the wide energy band from 10 keV to 700 keV with an extremely low background. The HSD is a compound-eye detector, employing 16 GSO/BGO well-type phoswich scintillation counters together with 64 silicon PIN detectors. The scintillation counters cover an energy range of 40-700 keV, while the PIN diodes fill the intermediate energy range from 10 keV to 70 keV with an energy resolution about 3 keV. In this paper, we report on the developments of the large area, thick silicon PIN diodes. In order to achieve a high quantum efficiency up to 70 keV with a high energy resolution, we utilize a double stack of silicon PIN diodes, each 20 x 20 mm(2) in size and 2 mm thick. Signals from the two diodes are summed into a single output. Four of these stacks (or eight diodes) are placed inside the deep EGO active-shield well of a phoswich counter, to achieve an extremely low background environment. Thus, the HXD utilizes 64 stacked silicon PIN detectors, achieving a total geometrical collecting area of 256 cm(2) We have developed the 2 mm thick silicon PIN diodes which have a low leakage current, a low capacitance, and a high breakdown voltage to meet the requirements of our goal. Through various trials in fabricating PIN diodes with different structures, we have found optimal design parameters, such as mask design of the surface p(+) layer and the implantation process., 1997年, 3115, 244, 253, 研究論文（国際会議プロシーディングス）, 10.1117/12.277691

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• 査読あり, 英語, Publications of the Astronomical Society of Japan, Signatures of large-scale cold fronts in the optically-selected merging cluster HSC J085024+001536, Keigo Tanaka; Ryuichi Fujimoto; Nobuhiro Okabe; Ikuyuki Mitsuishi; Hiroki Akamatsu; Naomi Ota; Masamune Oguri; Atsushi J Nishizawa, We represent a joint X-ray, weak-lensing, and optical analysis of the optically-selected merging cluster, HSC J085024+001536, from the Subaru HSC-SSP survey. Both the member galaxy density and the weak-lensing mass map show that the cluster is composed of southeast and northwest components. The two-dimensional weak-lensing analysis shows that the southeast component is the main cluster, and the sub- and main-cluster mass ratio is $0.32^{+0.75}_{-0.23}$. The northwest subcluster is offset by $\sim700$ kpc from the main cluster center, and their relative line-of-sight velocity is $\sim1300\,{\rm km s^{-1 } }$ from spectroscopic redshifts of member galaxies. The X-ray emission is concentrated around the main cluster, while the gas mass fraction within a sphere of $1'$ radius of the subcluster is only $f_{\mathrm{gas } }=4.0^{+2.3}_{-3.3}\%$, indicating that the subcluster gas was stripped by ram pressure. X-ray residual image shows three arc-like excess patterns, of which two are symmetrically located at $\sim550$ kpc from the X-ray morphological center, and the other is close to the X-ray core. The excess close to the subcluster has a cold-front feature where dense-cold gas and thin-hot gas contact. The two outer excesses are tangentially elongated about $\sim 450-650$ kpc, suggesting that the cluster is merged with a non-zero impact parameter. Overall features revealed by the multi-wavelength datasets indicate that the cluster is at the second impact or later. Since the optically-defined merger catalog is unbiased for merger boost of the intracluster medium, X-ray follow-up observations will pave the way to understand merger physics at various phases., 2021年06月13日, 73, 3, 584, 595, 研究論文（学術雑誌）, 10.1093/pasj/psab022

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• 査読あり, 英語, Astronomy & Astrophysics, The Abell 3391/95 galaxy cluster system. A 15 Mpc intergalactic medium emission filament, a warm gas bridge, infalling matter clumps, and (re-) accelerated plasma discovered by combining SRG/eROSITA data with ASKAP/EMU and DECam data, T. H. Reiprich; A. Veronica; F. Pacaud; M. E. Ramos-Ceja; N. Ota; J. Sanders; M. Kara; T. Erben; M. Klein; J. Erler; J. Kerp; D. N. Hoang; M. Brüggen; J. Marvil; L. Rudnick; V. Biffi; K. Dolag; J. Aschersleben; K. Basu; H. Brunner; E. Bulbul; K. Dennerl; D. Eckert; M. Freyberg; E. Gatuzz; V. Ghirardini; F. Käfer; A. Merloni; K. Migkas; K. Nandra; P. Predehl; J. Robrade; M. Salvato; B. Whelan; A. Diaz-Ocampo; D. Hernandez-Lang; A. Zenteno; M. J. I. Brown; J. D. Collier; J. M. Diego; A. M. Hopkins; A. Kapinska; B. Koribalski; T. Mroczkowski; R. P. Norris; A. O’Brien; E. Vardoulaki, Context. Inferences about dark matter, dark energy, and the missing baryons all depend on the accuracy of our model of large-scale structure evolution. In particular, with cosmological simulations in our model of the Universe, we trace the growth of structure, and visualize the build-up of bigger structures from smaller ones and of gaseous filaments connecting galaxy clusters. Aims. Here we aim to reveal the complexity of the large-scale structure assembly process in great detail and on scales from tens of kiloparsecs up to more than 10 Mpc with new sensitive large-scale observations from the latest generation of instruments. We also aim to compare our findings with expectations from our cosmological model. Methods. We used dedicated SRG/eROSITA performance verification (PV) X-ray, ASKAP/EMU Early Science radio, and DECam optical observations of a ~15 deg² region around the nearby interacting galaxy cluster system A3391/95 to study the warm-hot gas in cluster outskirts and filaments, the surrounding large-scale structure and its formation process, the morphological complexity in the inner parts of the clusters, and the (re-)acceleration of plasma. We also used complementary Sunyaev-Zeldovich (SZ) effect data from the Planck survey and custom-made Galactic total (neutral plus molecular) hydrogen column density maps based on the HI4PI and IRAS surveys. We relate the observations to expectations from cosmological hydrodynamic simulations from the Magneticum suite. Results. We trace the irregular morphology of warm and hot gas of the main clusters from their centers out to well beyond their characteristic radii, r₂₀₀. Between the two main cluster systems, we observe an emission bridge on large scale and with good spatial resolution. This bridge includes a known galaxy group but this can only partially explain the emission. Most gas in the bridge appears hot, but thanks to eROSITA’s unique soft response and large field of view, we discover some tantalizing hints for warm, truly primordial filamentary gas connecting the clusters. Several matter clumps physically surrounding the system are detected. For the “Northern Clump,” we provide evidence that it is falling towards A3391 from the X-ray hot gas morphology and radio lobe structure of its central AGN. Moreover, the shapes of these X-ray and radio structures appear to be formed by gas well beyond the virial radius, r₁₀₀, of A3391, thereby providing an indirect way of probing the gas in this elusive environment. Many of the extended sources in the field detected by eROSITA are also known clusters or new clusters in the background, including a known SZ cluster at redshift z = 1. We find roughly an order of magnitude more cluster candidates than the SPT and ACT surveys together in the same area. We discover an emission filament north of the virial radius of A3391 connecting to the Northern Clump. Furthermore, the absorption-corrected eROSITA surface brightness map shows that this emission filament extends south of A3395 and beyond an extended X-ray-emitting object (the “Little Southern Clump”) towards another galaxy cluster, all at the same redshift. The total projected length of this continuous warm-hot emission filament is 15 Mpc, running almost 4 degrees across the entire eROSITA PV observation field. The Northern and Southern Filament are each detected at >4σ. The Planck SZ map additionally appears to support the presence of both new filaments. Furthermore, the DECam galaxy density map shows galaxy overdensities in the same regions. Overall, the new datasets provide impressive confirmation of the theoretically expected structure formation processes on the individual system level, including the surrounding warm-hot intergalactic medium distribution; the similarities of features found in a similar system in the Magneticum simulation are striking. Our spatially resolved findings show that baryons indeed reside in large-scale warm-hot gas filaments with a clumpy structure., 2021年03月, 647, A2, A2, 研究論文（学術雑誌）, 10.1051/0004-6361/202039590

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• 査読あり, 英語, Monthly Notices of the Royal Astronomical Society, Active gas features in three HSC-SSP CAMIRA clusters revealed by high angular resolution analysis of MUSTANG-2 SZE and XXL X-ray observations, Nobuhiro Okabe; Simon Dicker; Dominique Eckert; Tony Mroczkowski; Fabio Gastaldello; Yen-Ting Lin; Mark Devlin; Charles E Romero; Mark Birkinshaw; Craig Sarazin; Cathy Horellou; Tetsu Kitayama; Keiichi Umetsu; Mauro Sereno; Brian S Mason; John A ZuHone; Ayaka Honda; Hiroki Akamatsu; I-Non Chiu; Kotaro Kohno; Kai-Yang Lin; Elinor Medezinski; Satoshi Miyazaki; Ikuyuki Mitsuishi; Atsushi J Nishizawa; Masamune Oguri; Naomi Ota; Florian Pacaud; Marguerite Pierre; Jonathan Sievers; Vernesa Smolčić; Sara Stanchfield; Keigo Tanaka; Ryoichi Yamamoto; Chong Yang; Atsushi Yoshida, We present results from simultaneous modelling of high angular resolution GBT/MUSTANG-2 90 GHz Sunyaev–Zel’dovich effect (SZE) measurements and XMM-XXL X-ray images of three rich galaxy clusters selected from the HSC-SSP Survey. The combination of high angular resolution SZE and X-ray imaging enables a spatially resolved multicomponent analysis, which is crucial to understand complex distributions of cluster gas properties. The targeted clusters have similar optical richnesses and redshifts, but exhibit different dynamical states in their member galaxy distributions: a single-peaked cluster, a double-peaked cluster, and a cluster belonging to a supercluster. A large-scale residual pattern in both regular Compton-parameter y and X-ray surface brightness distributions is found in the single-peaked cluster, indicating a sloshing mode. The double-peaked cluster shows an X-ray remnant cool core between two SZE peaks associated with galaxy concentrations. The temperatures of the two peaks reach ∼20–30 keV in contrast to the cool core component of ∼2 keV, indicating a violent merger. The main SZE signal for the supercluster is elongated along a direction perpendicular to the major axis of the X-ray core, suggesting a minor merger before core passage. The SX and y distributions are thus perturbed at some level, regardless of the optical properties. We find that the integrated Compton y parameter and the temperature for the major merger are boosted from those expected by the weak-lensing mass and those for the other two clusters show no significant deviations, which is consistent with predictions of numerical simulations., 2020年12月31日, 501, 2, 1701, 1732, 研究論文（学術雑誌）, 10.1093/mnras/staa2330

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• 査読無し, その他, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, Super DIOS mission for exploring "dark baryon", Kosuke Sato; Takaya Ohashi; Yoshitaka Ishisaki; Yuichiro Ezoe; Shinya Yamada; Noriko Y. Yamasaki; Kazuhisa Mitsuda; Manabu Ishida; Yoshitomo Maeda; Yuki Nakashima; Ikuyuki Mitsuishi; Yuzuru Tawara; Ryuichi Fujimoto; Takeshi Go . Tsuru; Naomi Ota; Ken Osato; Shinya Nakashima; Yutaka Fujita; Daisuke Nagai; Kohji Yoshikawa; Nobuyuki Kawai; Kyoko Matsushita; Yuto Ichinohe; Yuusuke Uchida, We are studying an improved DIOS (Diffuse Intergalactic Oxygen Surveyor) program, Super DIOS, which is accepted for establishing the Research Group in ISAS/JAXA, for a launch year after 2030. The aim of Super DIOS is an X-ray quantitative exploration of”dark baryon” over several scales from circumgalactic medium, cluster outskirt to warm-hot intergalactic medium along the Cosmic web with mapping redshifted emission lines from mainly oxygen and other ions. These observations play key roles for investigating the physical condition, such as the energy flow and metal circulation, of most baryons in the Universe. This mission will perform wide field X-ray spectroscopy with a field of view of about 0.5-1 degree and energy resolution of a few eV with TES microcalorimeter, but with much improved angular resolution of about 10-15 arcseconds. We will also consider including a small gamma-ray burst monitor and a fast repointing system. We will have an international collaboration with US and Europe for all the onboard instruments., 2020年12月13日, 11444, 研究論文（国際会議プロシーディングス）, 10.1117/12.2561681

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• 査読無し, その他, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, Detail plans and preparations for the science operations of the XRISM mission, Yukikatsu Terada; Matthew P. Holland; Michael Loewenstein; Makoto S. Tashiro; Hiromitsu Takahashi; Masayoshi Nobukawa; Tsunefumi Mizuno; Takayuki Tamura; Shin'ichiro Uno; Shin Watanabe; Chris Baluta; Laura Burns; Ken Ebisawa; Satoshi Eguchi; Yasushi Fukazawa; Katsuhiro Hayashi; Ryo Iizuka; Satoru Katsuda; Takao Kitaguchi; Aya Kubota; Eric D. Miller; Koji Mukai; Shinya Nakashima; Kazuhiro Nakazawa; Hirokazu Odaka; Masanori Ohno; Naomi Ota; Rie Sato; Yasuharu Sugawara; Megumi Shidatsu; Tsubasa Tamba; Atsushi Tanimoto; Yuichi Terashima; Yohko Tsuboi; Yuusuke Uchida; Hideki Uchiyama; Shigeo Yamauchi; Tahir Yaqoob, © 2020 SPIE The XRISM is the X-ray astronomical mission led by JAXA/NASA/ESA with international participation, plan to be launched in 2022 (Japanese fiscal year), to quickly recover the high-resolution X-ray spectroscopy of astrophysical objects using the micro-calorimeter array after the failure of Hitomi. To enhance the scientific outputs of the mission, the Science Operations Team (SOT) is structured independently from the instrument teams and the mission operation team (MOT). The responsibilities of the SOT are summarized into four categories: 1) Guest observer program and data distributions, 2) Distribution of the analyses software and calibration database, 3) Guest observer supporting activities, and 4) the performance verification and optimization (PVO) activities. Before constructing the Operations Concept of the XRISM mission, the lessons on the Science Operations learned from the past Japanese X-ray missions (ASCA, Suzaku, and Hitomi) are reviewed, and 16 kinds of lessons are identified by the above categories: lessons on the importance of avoiding nonpublic (“animal”) tools, coding quality of public tools both on the engineering viewpoint and the calibration accuracy, tight communications with instrument teams and operations team, well-defined task division between scientists and engineers etc. Among these lessons, a) importance of the early preparations of the operations from the ground stage, b) construction of the independent team for the Science Operations from the instrument developments, and c) operations with well-defined duties by appointed members are recognized as the key lessons for XRISM. Then, i) the task division between the Mission and Science Operations and ii) the subgroup structure within the XRISM team are defined in detail as the XRISM Operations Concept. Then, following the Operations Concept, the detail plan of the Science Operations is designed as follows. The Science Operations tasks are shared among Japan, US, and Europe operated by three centers, the Science Operations Center (SOC) at JAXA, the Science Data Center (SDC) at NASA, and European Space Astronomy Centre (ESAC) at ESA. The SOT is defined as a combination of the SOC and SDC; the SOC is designed to perform tasks close to the spacecraft operations, such as spacecraft planning of science targets, quick-look health checks, pre-pipeline data processing, etc., and the SDC covers the tasks on the data calibration processing (pipeline processing), maintenance of the analysis tools etc. The data-archive and users-support activities are planned to be covered both by the SOC and SDC. Finally, the details of the Science Operations tasks and the tools for the Science Operations are also described in this paper. This information would be helpful for a construction of Science Operations of future X-ray missions., 2020年12月13日, 11444, 研究論文（国際会議プロシーディングス）, 10.1117/12.2560861

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• 査読無し, その他, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, The XRISM science data center: optimizing the scientific return from a unique x-ray observatory, Michael Loewenstein; Robert S. Hill; Matthew P. Holland; Eric D. Miller; Tahir Yaqoob; Trisha F. Doyle; Patricia L. Hall; Efrem Braun; Christopher J. Baluta; Koji Mukai; Yukikatsu Terada; Makoto S. Tashiro; Hiromitsu Takahashi; Masayoshi Nobukawa; Tsunefumi Mizuno; Takayuki Tamura; Shin'ichiro Uno; Shin Watanabe; Ken Ebisawa; Satoshi Eguchi; Yasushi Fukazawa; Ryo Iizuka; Satoru Katsuda; Takao Kitaguchi; Aya Kubota; Shinya Nakashima; Kazuhiro Nakazawa; Hirokazu Odaka; Masanori Ohno; Naomi Ota; Rie Sato; Yasuharu Sugawara; Megumi Shidatsu; Tsubasa Tamba; Yuichi Terashima; Yohko Tsuboi; Yuusuke Uchida; Hideki Uchiyama; Shigeo Yamauchi, © 2020 SPIE The X-Ray Imaging and Spectroscopy Mission, XRISM, is currently scheduled to launch in 2022 with the objective of building on the brief, but significant, successes of the ASTRO-H (Hitomi) mission in solving outstanding astrophysical questions using high resolution X-ray spectroscopy. The XRISM Science Operations Team (SOT) consists of the JAXA-led Science Operations Center (SOC) and NASA-led Science Data Center (SDC), which work together to optimize the scientific output from the Resolve high-resolution spectrometer and the Xtend wide-field imager through planning and scheduling of observations, processing and distribution of data, development and distribution of software tools and the calibration database (CaldB), support of ground and in-flight calibration, and support of XRISM users in their scientific investigations of the energetic universe. Here, we summarize the roles and responsibilities of the SDC and its current status and future plans. The Resolve instrument poses particular challenges due to its unprecedented combination of high spectral resolution and throughput, broad spectral coverage, and relatively small field-of-view and large pixel-size. We highlight those challenges and how they are being met., 2020年12月13日, 11444, 研究論文（国際会議プロシーディングス）, 10.1117/12.2560840

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• 査読無し, その他, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, Status of x-ray imaging and spectroscopy mission (XRISM), Makoto S. Tashiro; Hironori Maejima; Kenichi Toda; Richard L. Kelley; Lillian Reichenthal; Leslie Hartz; Robert Petre; Brian J. Williams; Matteo Guainazzi; Elisa Costantini; Ryuichi Fujimoto; Kiyoshi Hayashida; Joy Henegar-Leon; Matt Holland; Yoshitaka Ishisaki; Caroline Kilbourne; Mike Loewenstein; Kyoko Matsushita; Koji Mori; Takashi Okajima; F. Scott Porter; Gary Sneiderman; Yoh Takei; Yukikatsu Terada; Hiroshi Tomida; Hiroya Yamaguchi; Shin Watanabe; Hiroki Akamatsu; Yoshitaka Arai; Marc Audard; Hisamitsu Awaki; Iurii Babyk; Aya Bamba; Nobutaka Bando; Ehud Behar; Thomas Bialas; Rozenn Boissay-Malaquin; Laura Brenneman; Greg Brown; Edgar Canavan; Meng Chiao; Brian Comber; Lia Corrales; Renata Cumbee; Cor de Vries; Jan-Willem den Herder; Johannes Dercksen; Maria Diaz-Trigo; Michael DiPirro; Chris Done; Tadayasu Dotani; Ken Ebisawa; Megan Eckart; Dominique Eckert; Satoshi Eguchi; Teruaki Enoto; Yuichiro Ezoe; Carlo Ferrigno; Yutaka Fujita; Yasushi Fukazawa; Akihiro Furuzawa; Luigi Gallo; Nathalie Gorter; Martin Grim; Liyi Gu; Kouichi Hagino; Kenji Hamaguchi; Isamu Hatsukade; David Hawthorn; Katsuhiro Hayashi; Natalie Hell; Junko Hiraga; Edmund Hodges-Kluck; Takafumi Horiuchi; Ann Hornschemeier; Akio Hoshino; Yuto Ichinohe; Sayuri Iga; Ryo Iizuka; Manabu Ishida; Naoki Ishihama; Kumi Ishikawa; Kosei Ishimura; Tess Jaffe; Jelle Kaastra; Timothy Kallman; Erin Kara; Satoru Katsuda; Steven Kenyon; Mark Kimball; Takao Kitaguti; Shunji Kitamoto; Shogo Kobayashi; Akihide Kobayashi; Takayoshi Kohmura; Aya Kubota; Maurice Leutenegger; Muzi Li; Tom Lockard; Yoshitomo Maeda; Maxim Markevitch; Connor Martz; Hironori Matsumoto; Keiichi Matsuzaki; Dan McCammon; Brian McLaughlin; Brian McNamara; Joseph Miko; Eric Miller; Jon Miller; Kenji Minesugi; Shinji Mitani; Ikuyuki Mitsuishi; Misaki Mizumoto; Tsunefumi Mizuno; Koji Mukai; Hiroshi Murakami; Richard Mushotzky; Hiroshi Nakajima; Hideto Nakamura; Kazuhiro Nakazawa; Chikara Natsukari; Kenichiro Nigo; Yusuke Nishioka; Kumiko Nobukawa; Masayoshi Nobukawa; Hirofumi Noda; Hirokazu Odaka; Mina Ogawa; Takaya Ohashi; Masahiro Ohno; Masayuki Ohta; Atsushi Okamoto; Naomi Ota; Masanobu Ozaki; Stephane Paltani; Paul Plucinsky; Katja Pottschmidt; Michael Sampson; Takahiro Sasaki; Kosuke Sato; Rie Sato; Toshiki Sato; Makoto Sawada; Hiromi Seta; Yasuko Shibano; Maki Shida; Megumi Shidatsu; Shuhei Shigeto; Keisuke Shinozaki; Peter Shirron; Aurora Simionescu; Randall Smith; Kazunori Someya; Yang Soong; Keisuke Sugawara; Yasuharu Sugawara; Andy Szymkowiak; Hiromitsu Takahashi; Toshiaki Takeshima; Toru Tamagawa; Keisuke Tamura; Takaaki Tanaka; Atsushi Tanimoto; Yuichi Terashima; Yohko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Yuusuke Uchida; Hideki Uchiyama; Yoshihiro Ueda; Shinichiro Uno; Jacco Vink; Tomomi Watanabe; Michael Wittheof; Rob Wolfs; Shinya Yamada; Kazutaka Yamaoka; Noriko Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Keiichi Yanagase; Tahir Yaqoob; Susumu Yasuda; Tessei Yoshida; Nasa Yoshioka; Irina Zhuravleva, 2020年12月13日, 研究論文（国際会議プロシーディングス）, 10.1117/12.2565812

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• 査読あり, その他, Publications of the Astronomical Society of Japan, Hundreds of weak lensing shear-selected clusters from the Hyper Suprime-Cam Subaru Strategic Program S19A data, Masamune Oguri; Satoshi Miyazaki; Xiangchong Li; Wentao Luo; Ikuyuki Mitsuishi; Hironao Miyatake; Surhud More; Atsushi J Nishizawa; Nobuhiro Okabe; Naomi Ota; Andrés A Plazas Malagón; Yousuke Utsumi, We use the Hyper Suprime-Cam Subaru Strategic Program S19A shape catalog to construct weak lensing shear-selected cluster samples. From aperture mass maps covering ∼510 deg2 created using a truncated Gaussian filter, we construct a catalog of 187 shear-selected clusters that correspond to mass map peaks with signal-to-noise ratio larger than 4.7. Most of the shear-selected clusters have counterparts in optically selected clusters, from which we estimate the purity of the catalog to be higher than 95%. The sample can be expanded to 418 shear-selected clusters with the same signal-to-noise ratio cut by optimizing the shape of the filter function and by combining weak lensing mass maps created with several different background galaxy selections. We argue that dilution and obscuration effects of cluster member galaxies can be mitigated by using background source galaxy samples and adopting a filter function with its inner boundary larger than about 2'. The large samples of shear-selected clusters that are selected without relying on any baryonic tracer are useful for detailed studies of cluster astrophysics and cosmology., 2021年08月04日, 73, 4, 817, 829, 研究論文（学術雑誌）, 10.1093/pasj/psab047

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• その他, IEEE Transactions on Nuclear Science, Spatially dependent response of thick and large area p-i-n diode for ASTRO-E hard X-ray detector, M. Sugiho; T. Kamae; K. Makishima; T. Takahashi; T. Murakami; M. Tashiro; Y. Fukazawa; N. Iyomoto; H. Ozawa; A. Kubota; K. Nakazawa; K. Yamaoka; M. Kokubun; N. Ota; C. Tanihata; N. Isobe; Y. Terada; Y. Matsumoto; Y. Uchiyama; D. Yonetoku; I. Takahashi; J. Kotoku; S. Watanabe; Y. Ezoe, The ASTRO-E hard X-ray detector utilizes GSO(Gd2SiO5:Ce 0.5% mol)-BGO(Bi4Ge3O12) well-type phoswich counters [1] in compound-eye configuration to achieve an extremely low background level of about a few times 10-5 counts s-1 cm-2 keV-1. The GSO scintillators placed at the bottom of the BGO well observe photons in the energy range 30-600 keV. To cover the lower energy range of 10-60 keV, silicon p-i-n diodes of 2 mm in thickness and 21.5×21.5 mm2 in size were newly developed and placed in front of the GSO scintillators. The p-i-n diode exhibits complex spectral responses, including subpeak and low energy tail components. To examine the origin of these components, we measured the spatially resolved response of the p-i-n diode and confirmed that the subpeak and the low energy tail are related to the electrode structures and electric fields in the p-i-n diode, respectively., 2001年06月, 48, 3 I, 426, 429, 研究論文（国際会議プロシーディングス）, 10.1109/23.940093

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• 査読あり, 英語, Publications of the Astronomical Society of Japan, Do blue galaxy-clusters have hot intracluster gas?, Rana Misato; Yoshiki Toba; Naomi Ota; Naoaki Yamamoto; Tadayuki Kodama; Nobuhiro Okabe; Masamune Oguri; Ikuyuki Mitsuishi, We present herein a systematic X-ray analysis of blue galaxy clusters at z = 0.84 discovered by the Subaru telescope. The sample consisted of 43 clusters identified by combining red-sequence and blue-cloud surveys, covering a wide range of emitter fractions (i.e., 0.3-0.8). The spatial extent of the over-density region of emitter galaxies was approximately 1 Mpc in radius. The average cluster mass was estimated as 0.6(<1.5) × 1014 M⊙ from the stacked weak-lensing measurement. We analyzed the XMM-Newton archival data, and measured the X-ray luminosity of the hot intracluster medium. As a result, diffuse X-ray emission was marginally detected in 14 clusters, yielding an average luminosity of 5 × 1042 erg s-1. To the contrary, it was not significant in 29 clusters. The blue clusters were significantly fainter than the red-dominated clusters, and the X-ray luminosity did not show any meaningful correlation either with emitter fraction or richness. The X-ray surface brightness was low, but the amount of gas mass was estimated to be comparable to that observed in the 1013-1014 M⊙ cluster. Based on the results, we suggest that the blue clusters are at the early formation stage, and the gas is yet to be compressed and heated up to produce appreciable X-rays. Follow-up spectroscopic measurements are essential to clarify the dynamical status and co-evolution of galaxies and hot gas in the blue clusters., 2022年03月02日, 74, 2, 398, 406, 研究論文（学術雑誌）, 10.1093/pasj/psac002

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• 査読あり, 英語, Journal of Astronomical Telescopes, Instruments, and Systems, Detailed design of the science operations for the XRISM mission, Yukikatsu Terada; Matt Holland; Michael Loewenstein; Makoto Tashiro; Hiromitsu Takahashi; Masayoshi Nobukawa; Tsunefumi Mizuno; Takayuki Tamura; Shin’ichiro Uno; Shin Watanabe; Chris Baluta; Laura Burns; Ken Ebisawa; Satoshi Eguchi; Yasushi Fukazawa; Katsuhiro Hayashi; Ryo Iizuka; Satoru Katsuda; Takao Kitaguchi; Aya Kubota; Eric Miller; Koji Mukai; Shinya Nakashima; Kazuhiro Nakazawa; Hirokazu Odaka; Masanori Ohno; Naomi Ota; Rie Sato; Makoto Sawada; Yasuharu Sugawara; Megumi Shidatsu; Tsubasa Tamba; Atsushi Tanimoto; Yuichi Terashima; Yohko Tsuboi; Yuusuke Uchida; Hideki Uchiyama; Shigeo Yamauchi; Tahir Yaqoob, X-Ray Imaging and Spectroscopy Mission (XRISM) is an x-ray astronomical mission led by the Japan Aerospace Exploration Agency (JAXA) and National Aeronautics and Space Administration (NASA), with collaboration from the European Space Agency (ESA) and other international participants, that is planned for launch in 2022 (Japanese fiscal year), to quickly restore high-resolution x-ray spectroscopy of astrophysical objects using the microcalorimeter array after the loss of Hitomi satellite. In order to enhance the scientific outputs of the mission, the Science Operations Team (SOT) is structured independently from the Instrument Teams (ITs) and the Mission Operations Team. The responsibilities of the SOT are divided into four categories: (1) guest observer program and data distributions, (2) distribution of analysis software and the calibration database, (3) guest observer support activities, and (4) performance verification and optimization activities. Before constructing the operations concept of the XRISM mission, lessons on the science operations learned from past Japanese x-ray missions (ASCA, Suzaku, and Hitomi) are reviewed, and 15 kinds of lessons are identified by categories, such as lessons on the importance of avoiding non-public ("animal") tools, coding quality of public tools in terms of the engineering viewpoint and calibration accuracy, tight communications with ITs and operations teams, and well-defined task division between scientists and engineers. Among these lessons, (a) the importance of early preparation of the operations from the ground stage, (b) construction of an independent team for science operations separate from the instrument development, and (c) operations with well-defined duties by appointed members are recognized as key lessons for XRISM. Based on this, (i) the task division between the mission and science operations and (ii) the subgroup structure within the XRISM Team are defined in detail as the XRISM operations concept. Based on this operations concept, the detailed plan of the science operations is designed as follows. The science operations tasks are shared among Japan, the USA, and Europe and are performed by three centers: the Science Operations Center (SOC) at JAXA, the Science Data Center (SDC) at NASA, and European Space Astronomy Centre (ESAC) at the ESA. The SOT is defined as a combination of the SOC and SDC. The SOC is designed to perform tasks close to the spacecraft operations, such as spacecraft planning of science targets, quick-look health checks, and prepipeline data processing. The SDC covers tasks regarding data calibration processing (pipeline processing) and maintenance of analysis tools. The data-archive and user-support activities are planned to be covered both by the SOC and SDC. Finally, the details of the science operations tasks and the tools for science operations are defined and prepared before launch. This information is expected to be helpful for the construction of science operations of future x-ray missions. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI., 2021年07月01日, 7, 03, 研究論文（学術雑誌）, 10.1117/1.jatis.7.3.037001

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• その他, Publications of the Astronomical Society of Japan, Erratum to: Suzaku Observations of Low Surface Brightness Cluster Abell 1631 (Publications of the Astronomical Society of Japan (2018) DOI: 10.1093/pasj/psy036), Yasunori Babazaki; Ikuyuki Mitsuishi; Naomi Ota; Shin Sasaki; Hans Böhringer; Gayoung Chon; Gabriel W. Pratt; Hironori Matsumoto, In the Advance Access version of this paper [doi: 10.1093/pasj/psy036, published online 10 April 2018], the following error occurred: unnecessary parameters appeared in table 2. This error has been corrected for the final published version. The authors apologize for these errors., 2018年06月01日, 70, 3, 研究論文（学術雑誌）, 10.1093/pasj/psy063

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• その他, SPIE Proceedings, DIOS: the dark baryon exploring mission, T. Ohashi; Y. Ishisaki; Y. Ezoe; S. Yamada; G. Kuromaru; S. Suzuki; Y. Tawara; I. Mitsuishi; Y. Babazaki; K. Mitsuda; N. Y. Yamasaki; Y. Takei; R. Yamamoto; T. Hayashi; N. Ota; R. L. Kelley; K. Sakai, 2016年07月18日, 研究論文（国際会議プロシーディングス）, 10.1117/12.2232274

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• 査読あり, 英語, Astronomy and Astrophysics, The eROSITA Final Equatorial-Depth Survey (eFEDS): A complete census of X-ray properties of Subaru Hyper Suprime-Cam weak lensing shear-selected clusters in the eFEDS footprint, M. E. Ramos-Ceja; M. Oguri; S. Miyazaki; V. Ghirardini; I. Chiu; N. Okabe; A. Liu; T. Schrabback; D. Akino; Y. E. Bahar; E. Bulbul; N. Clerc; J. Comparat; S. Grandis; M. Klein; Y. T. Lin; A. Merloni; I. Mitsuishi; H. Miyatake; S. More; K. Nandra; A. J. Nishizawa; N. Ota; F. Pacaud; T. H. Reiprich; J. S. Sanders, Context. The eFEDS survey is a proof-of-concept mini-survey designed to demonstrate the survey science capabilities of SRG/eROSITA. It covers an area of 140 deg2 where ~540 galaxy clusters have been detected out to a redshift of 1.3. The eFEDS field is partly embedded in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) S19A data release, which covers ~510 deg2, containing approximately 36 million galaxies. This galaxy catalogue has been used to construct a sample of ~180 shear-selected galaxy clusters. The common area to both surveys covers about 90 deg2, making it an ideal region to study galaxy clusters selected in different ways. Aims. The aim of this work is to investigate the effects of selection methods in the galaxy cluster detection by comparing the X-ray selected, eFEDS, and the shear-selected, HSC-SSP S19A, galaxy cluster samples. There are 25 shear-selected clusters in the eFEDS fooprint. Methods. The relation between X-ray bolometric luminosity and weak-lensing mass is investigated (Lbol - M relation), comparing this relation derived from a shear-selected cluster sample to the relation obtained from an X-ray selected sample. Moreover, the dynamical state of the shear-selected clusters is investigated and compared to the X-ray selected sample using X-ray morphological parameters and galaxy distribution. Results. The normalisation of the Lbol â ? ? M relation of the X-ray selected and shear-selected samples is consistent within 1Ï ? -. Moreover, the dynamical state and merger fraction of the shear-selected clusters is not different from the X-ray selected ones. Four shear-selected clusters are undetected in X-rays. A close inspection reveals that one is the result of projection effects, while the other three have an X-ray flux below the ultimate eROSITA detection limit. Finally, 43% of the shear-selected clusters lie in superclusters. Conclusions. Our results indicate that the scaling relation between X-ray bolometric luminosity and true cluster mass of the shear-selected cluster sample is consistent with the eFEDS sample. There is no significant population of X-ray underluminous clusters, indicating that X-ray selected cluster samples are complete and can be used as an accurate cosmological probe., 2022年05月01日, 661, 研究論文（学術雑誌）, 10.1051/0004-6361/202142214

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• 査読あり, 英語, Astronomy & Astrophysics, The eROSITA Final Equatorial-Depth Survey (eFEDS), A. Liu; E. Bulbul; V. Ghirardini; T. Liu; M. Klein; N. Clerc; Y. Özsoy; M. E. Ramos-Ceja; F. Pacaud; J. Comparat; N. Okabe; Y. E. Bahar; V. Biffi; H. Brunner; M. Brüggen; J. Buchner; J. Ider Chitham; I. Chiu; K. Dolag; E. Gatuzz; J. Gonzalez; D. N. Hoang; G. Lamer; A. Merloni; K. Nandra; M. Oguri; N. Ota; P. Predehl; T. H. Reiprich; M. Salvato; T. Schrabback; J. S. Sanders; R. Seppi; Q. Thibaud, Aims.The eROSITA Final Equatorial-Depth Survey has been carried out during the performance verification phase of the Spectrum-Roentgen-Gamma/eROSITA telescope and was completed in November 2019. This survey is designed to provide the first eROSITA-selected sample of clusters and groups and to test the predictions for the all-sky survey in the context of cosmological studies with clusters of galaxies. Methods.In the area of ~140 square degrees covered by eFEDS, 542 candidate clusters and groups of galaxies were detected as extended X-ray sources with theeSASSsource detection algorithm. We performed imaging and spectral analysis of the 542 cluster candidates with eROSITA X-ray data and studied the properties of the sample. Results.We provide the catalog of candidate galaxy clusters and groups detected by eROSITA in the eFEDS field down to a flux of ~10^–14erg s^–1cm^–2in the soft band (0.5^–2 keV) within 1’. The clusters are distributed in the redshift range ɀ=[0.01, 1.3] with a median redshift ɀ_median= 0.35. With eROSITA X-ray data, we measured the temperature of the intracluster medium within two radii, 300 kpc and 500 kpc, and constrained the temperature with >2σconfidence level for ~1/5 (102 out of 542) of the sample. The average temperature of these clusters is ~2 keV. Radial profiles of flux, luminosity, electron density, and gas mass were measured from the precise modeling of the imaging data. The selection function, the purity, and the completeness of the catalog are examined and discussed in detail. The contamination fraction is ~1/5 in this sample and is dominated by misidentified point sources. The X-ray luminosity function of the clusters agrees well with the results obtained from other recent X-ray surveys. We also find 19 supercluster candidates in this field, most of which are located at redshifts between 0.1 and 0.5, including one cluster at ɀ ~ 0.36 that was presented previously. Conclusions.The eFEDS cluster and group catalog at the final eRASS equatorial depth provides a benchmark proof of concept for the eROSITA All-Sky Survey extended source detection and characterization. We confirm the excellent performance of eROSITA for cluster science and expect no significant deviations from our pre-launch expectations for the final all-sky survey., 2022年05月18日, 661, A2, A2, 研究論文（学術雑誌）, 10.1051/0004-6361/202141120

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• 査読あり, 英語, Astronomy and Astrophysics, The eROSITA Final Equatorial-Depth Survey (eFEDS): Optical confirmation, redshifts, and properties of the cluster and group catalog, M. Klein; M. Oguri; J. J. Mohr; S. Grandis; V. Ghirardini; T. Liu; A. Liu; E. Bulbul; J. Wolf; J. Comparat; M. E. Ramos-Ceja; J. Buchner; I. Chiu; N. Clerc; A. Merloni; H. Miyatake; S. Miyazaki; N. Okabe; N. Ota; F. Pacaud; M. Salvato; S. P. Driver, Context. In 2019, the eROSITA telescope on board the Russian-German satellite Spectrum-Roentgen-Gamma (SRG) began to perform a deep all-sky X-ray survey with the aim of identifying ~100 000 clusters and groups over the course of four years. As part of its performance verification phase, a ~140 deg2 survey, called eROSITA Final Equatorial-Depth Survey (eFEDS), was performed. With a depth typical of the all-sky survey after four years, it allows tests of tools and methods as well as improved predictions for the all-sky survey. Aims. As part of this effort, a catalog of 542 X-ray selected galaxy group and cluster candidates was compiled. In this paper we present the optical follow-up, with the aim of providing redshifts and cluster confirmation for the full sample. Furthermore, we aim to provide additional information on the dynamical state, richness, and optical center of the clusters. Finally, we aim to evaluate the impact of optical cluster confirmation on the purity and completeness of the X-ray selected sample. Methods. We used optical imaging data from the Hyper Suprime-Cam Subaru Strategic Program and from the Legacy Survey to identify optical counterparts to the X-ray detected cluster candidates. We make use of the multi-component matched filter cluster confirmation tool (MCMF), as well as of the optical cluster finder CAMIRA to derive cluster redshifts and richnesses. MCMF provided the probabilities with which an optical structure would be a chance superposition with the X-ray candidate. These probabilities were used to identify the best optical counterpart as well as to confirm an X-ray candidate as a cluster. The impact of this confirmation process on catalog purity and completeness was estimated using optical to X-ray scaling relations as well as simulations. The resulting catalog was furthermore matched with public group and cluster catalogs. Optical estimators of the cluster dynamical state were constructed based on density maps of the red-sequence galaxies at the cluster redshift. Results. By providing redshift estimates for all 542 candidates, we construct an optically confirmed sample of 477 clusters and groups with a residual contamination of 6%. Of these, 470 (98.5%) are confirmed using MCMF, and 7 systems are added through cross-matching with spectroscopic group catalogs. Using observable-to-observable scaling and the applied confirmation threshold, we predict that 8 ± 2 real systems have been excluded with the MCMF cut required to build this low-contamination sample. This number agrees well with the 7 systems found through cross-matching that were not confirmed with MCMF. The predicted redshift and mass distribution of this catalog agree well with simulations. Thus, we expect that these 477 systems include >99% of all true clusters in the candidate list. Using an MCMF-independent method, we confirm that the catalog contamination of the confirmed subsample is 6 ± 3%. Application of the same method to the full candidate list yields 17 ± 3%, consistent with estimates coming from the fraction of confirmed systems of ~17% and with expectations from simulations of ~20%. We also present a sample of merging cluster candidates based on the derived estimators of the cluster dynamical state., 2022年05月01日, 661, 研究論文（学術雑誌）, 10.1051/0004-6361/202141123

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• 査読無し, 英語, Astronomy and Astrophysics, Investigating the hard X-ray emission from the hottest Abell cluster A2163 with Suzaku, N. Ota; K. Nagayoshi; G. W. Pratt; T. Kitayama; T. Oshima; T. H. Reiprich, Context. We present the results from Suzaku of the hottest Abell galaxy cluster A2163 at z = 0.2. Aims. To study the physics of gas heating in cluster mergers, we investigated hard X-ray emission from the merging cluster A2163, which hosts the brightest synchrotron radio halo. Methods. We analyzed hard X-ray emission spectra accumulated from two-pointed Suzaku observations. Non-thermal hard X-ray emission should result from the inverse Compton scattering of relativistic electrons by photons in the cosmic microwave background. To measure this emission, the dominant thermal emission in the hard X-ray band must be modeled in detail. To this end, we analyzed the combined broadband X-ray data of A2163 collected by Suzaku and XMM-Newton, assuming single-and multi-temperature models for thermal emission and the power-law model for non-thermal emission. Comparing the non-thermal hard X-ray flux to radio synchrotron emission, we also estimated the magnetic field in the cluster. Results. From the Suzaku data, we detected significant hard X-ray emission from A2163 in the 12-60 keV band at the 28σ level (or at the 5.5σ level if a systematic error of the non-X-ray background model is considered). The Suzaku HXD spectrum alone is consistent with the single-temperature thermal model of gas temperature kT = 14 keV. From the XMM-Newton data, we constructed a multi-temperature model including a very hot (kT = 18 keV) component in the north-east region. Incorporating the multi-temperature and the power-law models into a two-component model with a radio-band photon index, where Γ = 2.18, the 12-60 keV energy flux of non-thermal emission is constrained within 5.3 ± 0.9 (±3.8) × 10-12 erg s-1cm -2 (the first and second errors refer to the 1σ statistical and systematic uncertainties, respectively). The 90% upper limit of detected inverse Compton emission is marginal (FNT < 1.2 × 10 -11 erg s-1cm-2 in the 12-60 keV band). The estimated magnetic field in A2163 is B > 0.098 μG. While the present results represent a three-fold increase in the accuracy of the broadband (0.3-60 keV) spectral model of A2163, more sensitive hard X-ray observations are needed to decisively test for the presence of hard X-ray emission due to inverse Compton emission. © 2014 ESO., 2014年02月, 562, A60, 研究論文（学術雑誌）, 10.1051/0004-6361/201322878

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• 査読あり, 英語, Publications of the Astronomical Society of Japan, Optical IFU observations of GOALS sample with KOOLS-IFU on Seimei Telescope: Initial results of nine U/LIRGs at z<0.04, Yoshiki Toba; Satoshi Yamada; Kazuya Matsubayashi; Koki Terao; Aoi Moriya; Yoshihiro Ueda; Kouji Ohta; Aoi Hashiguchi; Kazuharu G Himoto; Hideyuki Izumiura; Kazuma Joh; Nanako Kato; Shuhei Koyama; Hiroyuki Maehara; Rana Misato; Akatoki Noboriguchi; Shoji Ogawa; Naomi Ota; Mio Shibata; Nozomu Tamada; Anri Yanagawa; Naoki Yonekura; Tohru Nagao; Masayuki Akiyama; Masaru Kajisawa; Yoshiki Matsuoka, Abstract We present ionized gas properties of nine local ultra/luminous infrared galaxies (U/LIRGs) at z &lt; 0.04 through Integral Field Unit (IFU) observations with KOOLS-IFU on the Seimei Telescope. The observed targets are drawn from the Great Observatories All-sky LIRG Survey (GOALS), covering a wide range of merger stages. We successfully detect emission lines such as Hβ, [O iii]λ5007, Hα, [N ii]λλ6549, 6583, and [S ii]λλ6717, 6731 with a spectral resolution of R = 1500–2000, which provides (i) a spatially resolved (∼200–700 pc) moment map of ionized gas and (ii) diagnostics for an active galactic nucleus (AGN) within the central ∼3–11 kpc in diameter for our sample. We find that the [O iii] outflow that is expected to be driven by an AGN tends to be stronger (i) towards the galactic center and (ii) as a sequence of the merger stage. In particular, the outflow strength in the late-stage (stage D) mergers is about 1.5 times stronger than that in the early-state (stage B) mergers, which indicates that galaxy mergers could induce AGN-driven outflow and play an important role in the co-evolution of galaxies and supermassive black holes., 2022年12月01日, 74, 6, 1356, 1367, 研究論文（学術雑誌）, 10.1093/pasj/psac073

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• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 23pDK-4 ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(VI), 石崎 欣尚; 満田 和久; 山崎 典子; 竹井 洋; 辻本 匡弘; 小川 美奈; 杉田 寛之; 佐藤 洋一; 篠崎 慶亮; 岡本 篤; 藤本 龍一; 大橋 隆哉; 江副 祐一郎; 山田 真也; 小波 さおり; 田代 信; 寺田 幸功; 瀬田 裕美; 北本 俊二; 星野 晶夫; 玉川 徹; 石川 久美; 野田 博文; 佐藤 浩介; 太田 直美; 澤田 真理; 三石 郁之; 村上 正秀; 村上 弘志; 伊豫本 直子; Kelley R.L.; Kilbourne C.A.; Porter F.S.; Boyce K.R.; Eckart M.E.; Chiao M.P.; Leutenegger M.A.; Brown G.V.; McCammon D.; Szymkowiak A.; Herder J.-W. den; Haas D.; de Vries C.; Costantini E.; Akamatsu H.; Paltani S.; ASTRO-H SXSチーム, 2015年, 70, 471, 471, 10.11316/jpsgaiyo.70.1.0_471

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• 査読あり, 英語, Astronomy & Astrophysics, The eROSITA Final Equatorial-Depth Survey (eFEDS). X-ray properties of Subaru's optically selected clusters, N. Ota; N. T. Nguyen-Dang; I. Mitsuishi; M. Oguri; M. Klein; N. Okabe; M. E. Ramos-Ceja; T. H. Reiprich; F. Pacaud; E. Bulbul; M. Brüggen; A. Liu; K. Migkas; I. Chiu; V. Ghirardini; S. Grandis; Y.-T. Lin; H. Miyatake; S. Miyazaki; J. S. Sanders, Context. We present the results of a systematic X-ray analysis of optically rich galaxy clusters detected by the Subaru Hyper Suprime-Cam (HSC) survey in the eROSITA Final Equatorial-Depth Survey (eFEDS) field. Aims. Through a joint analysis of the SRG (Spectrum Roentgen Gamma)/eROSITA and Subaru/HSC surveys, we aim to investigate the dynamical status of the optically selected clusters and to derive the cluster scaling relations. Methods. The sample consists of 43 optically selected galaxy clusters with a richness >40 in the redshift range of 0.16–0.89. We systematically analyzed the X-ray images and emission spectra using the eROSITA data. We identified the brightest cluster galaxy (BCG) using the optical and far-infrared databases. We evaluated the cluster’s dynamical status by measuring three quantities: offset between the X-ray peak and BCG position, the gas concentration parameter, and the number of galaxy-density peaks. We investigated the luminosity–temperature and mass–luminosity relations based on eROSITA X-ray spectra and HSC weak-lensing data analyses. Results. Based on these three measurements, we estimated the fraction of relaxed clusters to be 2(< 39)%, which is smaller than that of the X-ray-selected cluster samples. After correcting for a selection bias due to the richness cut, we obtained a shallow L−T slope of 2.1 ± 0.5, which is consistent with the predictions of the self-similar model and the baseline model incorporating a mass–concentration relation. The L−M slope of 1.5 ± 0.3 is in agreement with the above-cited theoretical models as well as the data on the shear-selected clusters in the eFEDs field. Conclusions. Our analysis of high-richness optical clusters yields a small fraction of relaxed clusters and a shallow slope for the luminosity–temperature relation. This suggests that the average X-ray properties of the optical clusters are likely to be different from those observed in the X-ray samples. Thus, the joint eROSITA and HSC observations are a powerful tool in extending the analysis to a larger sample and understanding the selection effect with a view to establish cluster scaling relations., 2023年01月18日, 669, A110, A110, 研究論文（学術雑誌）, 10.1051/0004-6361/202244260

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• 査読あり, 英語, Journal of Low Temperature Physics, Super DIOS Project for Exploring “Dark Baryon”, K. Sato; N. Y. Yamasaki; M. Ishida; Y. Maeda; K. Mitsuda; Y. Ishisaki; Y. Fujita; Y. Ezoe; I. Mitsuishi; Y. Tawara; K. Osato; N. Kawai; K. Matsushita; D. Nagai; K. Yoshikawa; R. Fujimoto; T. G. Tsuru; N. Ota; S. Yamada; Y. Ichinohe; Y. Uchida; Y. Nakashima, 2022年11月09日, 209, 5-6, 971, 979, 研究論文（学術雑誌）, 10.1007/s10909-022-02910-w

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• 査読無し, 英語, Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray, A broadband x-ray imaging spectroscopy in the 2030s: the FORCE mission, Koji Mori; Takeshi G. Tsuru; Kazuhiro Nakazawa; Yoshihiro Ueda; Shin Watanabe; Takaaki Tanaka; Manabu Ishida; Hironori Matsumoto; Hisamitsu Awaki; Hiroshi Murakami; Masayoshi Nobukawa; Ayaki Takeda; Yasushi Fukazawa; Hiroshi Tsunemi; Tadayuki Takahashi; Ann E. Hornschemeier; Takashi Okajima; William W. Zhang; Brian J. Williams; Tonia Venters; Kristin Madsen; Mihoko Yukita; Hiroki Akamatsu; Aya Bamba; Teruaki Enoto; Yutaka Fujita; Akihiro Furuzawa; Kouichi Hagino; Kosei Ishimura; Masayuki Itoh; Tetsu Kitayama; Shogo B. Kobayashi; Takayoshi Kohmura; Aya Kubota; Misaki Mizumoto; Tsunefumi Mizuno; Hiroshi Nakajima; Kumiko K. Nobukawa; Hirofumi Noda; Hirokazu Odaka; Naomi Ota; Toshiki Sato; Megumi Shidatsu; Hiromasa Suzuki; Hiromitsu Takahashi; Atsushi Tanimoto; Yukikatsu Terada; Yuichi Terashima; Hiroyuki Uchida; Yasunobu Uchiyama; Hiroya Yamaguchi; Yoichi Yatsu, 2022年08月31日, 12181, 研究論文（国際会議プロシーディングス）, 10.1117/12.2628772

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• 査読無し, 英語, Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray, Super DIOS for exploring dark baryon, Kosuke Sato; Noriko Y. Yamasaki; Shinya Yamada; Ikuyuki Mitsuishi; Yuto Ichinohe; Hajime Omamiuda; Yuusuke Uchida; Kazuhisa Mitsuda; Daisuke Nagai; Kohji Yoshikawa; Ken Osato; Kyoko Matsushita; Yutaka Fujita; Yoshitaka Ishisaki; Yuichiro Ezoe; Manabu Ishida; Yoshitomo Maeda; Nobuyuki Kawai; Ryuichi Fujimoto; Takeshi G. Tsuru; Naomi Ota; Yuki Nakashima, 2022年08月31日, 12181, 研究論文（国際会議プロシーディングス）, 10.1117/12.2629066

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• 査読無し, 英語, Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray, Xappl: software framework for the XRISM pre-pipeline, Satoshi Eguchi; Makoto Tashiro; Yukikatsu Terada; Hiromitsu Takahashi; Masayoshi Nobukawa; Tsunefumi Mizuno; Shin'ichiro Uno; Aya Kubota; Kazuhiro Nakazawa; Shin Watanabe; Ryo Iizuka; Rie Sato; Tomokage Yoneyama; Chris Baluta; Ken Ebisawa; Yasushi Fukazawa; Katsuhiro Hayashi; So Kato; Satoru Katsuda; Takao Kitaguchi; Hirokazu Odaka; Masanori Ohno; Naomi Ota; Minami Sakama; Ryohei Sato; Megumi Shidatsu; Yasuharu Sugawara; Tsubasa Tamba; Atsushi Tanimoto; Yuichi Terashima; Yohko Tsuboi; Nagomi Uchida; Yuusuke Uchida; Hideki Uchiyama; Shigeo Yamauchi; Masaaki Sakano; Tessei Yoshida; Satoshi Yamada, 2022年08月31日, 12181, 研究論文（国際会議プロシーディングス）, 10.1117/12.2629316

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• 査読あり, 英語, Astronomy & Astrophysics, X-ray studies of the Abell 3158 galaxy cluster with eROSITA, B. Whelan; A. Veronica; F. Pacaud; T. H. Reiprich; E. Bulbul; M. E. Ramos-Ceja; J. S. Sanders; J. Aschersleben; J. Iljenkarevic; K. Migkas; M. Freyberg; K. Dennerl; M. Kara; A. Liu; V. Ghirardini; N. Ota, Context. The most nearby clusters are the best places for studying physical and enrichment effects in the faint cluster outskirts. The Abell 3158 cluster (A3158), located at z = 0.059, is quite extended with a characteristic radius r₂₀₀ = 23.95 arcmin. The metal distribution in the outskirts of this cluster has previously been studied with XMM-Newton. In 2019, A3158 was observed as a calibration target in a pointed observation with the eROSITA telescope on board the Spektrum-Roentgen-Gamma mission. Bright large clusters, such as A3158, are ideal for studying the metal distribution in the cluster outskirts, along with the temperature profile and morphology. With the deeper observation time of the eROSITA telescope, these properties can now be studied in greater detail and at larger radii. Furthermore, bright nearby clusters are ideal X-ray instrumental cross-calibration targets as they cover a large fraction of the detector and do not vary in time. Aims. We first compare the temperature, metal abundance, and normalisation profiles of the cluster from eROSITA with previous XMM-Newton and Chandra data. Following this calibration work, we investigate the temperature and metallicity of the cluster out to almost r₂₀₀, measure the galaxy velocity dispersion, and determine the cluster mass. Furthermore, we search for infalling clumps and background clusters in the field. Methods. We determined 1D temperature, abundance, and normalisation profiles from both eROSITA and XMM-Newton data as well as 2D maps of temperature and metal abundance distribution from eROSITA data. The velocity dispersion was determined and the cluster mass was calculated from the mass–velocity dispersion (M₂₀₀−σ_υ) relation. Galaxy density maps were created to enable a better understanding of the structure of the cluster and the outskirts. Results. The overall (i.e. in the range 0.2−0.5r₅₀₀) temperature was measured to be 5.158 ± 0.038 keV. The temperature, abundance, and normalisation profiles of eROSITA all agree to within a confidence level of about 10% with those we determined using XMM-Newton and Chandra data, and they are also consistent with the profiles published previously by the X-COP project. The cluster morphology and surface brightness profile of cluster Abell 3158 appear to be regular at a first glance. Clusters that have such profiles typically are relaxed and host cool cores. However, the temperature profile and map show that the cluster lacks a cool core, as was noted before. Instead, an off-centre cool clump lies to the west of the central cluster region, as reported previously. These are indications that the cluster may be undergoing some sloshing and merger activity. Furthermore, there is a bow-shaped edge near the location of the cool gas clump west of the cluster centre. Farther out west of the X-ray images of A3158, an extension of gas is detected. This larger-scale extension is described here for the first time. The gas metallicity (~0.2 solar) measured in the outskirts (»r₅₀₀) is consistent with an early-enrichment scenario. The velocity dispersion of the cluster member galaxies is measured to be 1058 ± 41 kms⁻¹ based on spectroscopic redshifts of 365 cluster member galaxies and the total mass is determined as M_200,c = 1.38 ± 0.25 × 10¹⁵M_⊙. The mass estimate based on the X-ray temperature is significantly lower at M₂₀₀ = 6.20 ± 0.75 × 10¹⁴M_⊙, providing further indications that merger activity boosts the velocity dispersion and/or biases the temperature low. An extended X-ray source located south of the field of view also coincides with a galaxy overdensity with spectroscopic redshifts in the range 0.05 < z < 0.07. This source further supports the idea that the cluster is undergoing merger activity. Another extended source located north of the field of view is detected in X-rays and coincides with an overdensity of galaxies with spectroscopic redshifts in the range of 0.070 < z < 0.077. This is likely a background cluster that is not directly related to A3158. Additionally, the known South Pole Telescope cluster SPT-CL J0342-5354 at z = 0. 53 was detected., 2022年07月, 663, A171, A171, 研究論文（学術雑誌）, 10.1051/0004-6361/202141621

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• 査読あり, 英語, Astronomy & Astrophysics, The eROSITA view of the Abell 3391/95 field: Case study from the Magneticum cosmological simulation, Veronica Biffi; Klaus Dolag; Thomas H. Reiprich; Angie Veronica; Miriam E. Ramos-Ceja; Esra Bulbul; Naomi Ota; Vittorio Ghirardini, Context.Clusters of galaxies reside at the nodes of the cosmic web, interconnected by filamentary structures that contain tenuous diffuse gas, especially in the warm-hot phase. Galaxy clusters grow by mergers of smaller objects and gas that are mainly accreted through these large-scale filaments. For the first time, the large-scale cosmic structure and a long gas-emission filament have been captured by eROSITA on board the Spectrum-Roentgen-Gamma mission in a direct X-ray observation of the A3391/95 field. Aims.We investigate the assembly history of an A3391/95-like system of clusters and the thermo-chemical properties of the diffuse gas in it by connecting simulation predictions to the eROSITA observations with the aim to constrain the origin and nature of the gas in the pair-interconnecting bridge. Methods.We analysed the properties of a system resembling A3391/95, extracted from the (352h⁻¹cMpc)³volume of the Magneticum Pathfinder cosmological simulations atz= 0.07. We tracked the main progenitors of the pair clusters and of surrounding groups back in time to study the assembly history of the system and its evolution. Results.Similarly to the observed A3391/95 system, the simulated cluster pair is embedded in a complex network of gas filaments, with structures aligned over more than 20 projected Mpc, and the whole region collapses towards the central overdense node. The spheres of influence (3 ×R₂₀₀) of the two main clusters already overlap atz= 0.07, but their virial boundaries are still physically separated. The diffuse gas located in the interconnecting bridge closely reflects the warm-hot intergalactic medium, with a typical temperature of ~1 keV and an overdensityδ ~100 with respect to the mean baryon density of the Universe, and a lower enrichment level compared to the intra-cluster medium in clusters. We find that most of the bridge gas collapsed from directions roughly orthogonal to the intra-cluster gas accretion directions, and its origin is mostly unrelated to the two cluster progenitors. We find clear signatures in the surrounding groups of infall motion towards the pair, such as significant radial velocities and a slowdown of gas compared to dark matter. These findings further support the hypothesis that the Northern Clump (MCXC J0621.7-5242) cluster infalls along a cosmic gas filament towards Abell 3391 and might be merging with it. Conclusions.We conclude that in this configuration, the pair clusters of the A3391/95-like system are in a pre-merger phase and have not yet interacted. The diffuse gas in the interconnecting bridge is mostly warm filament gas and not tidally stripped cluster gas., 2022年05月18日, 661, A17, A17, 研究論文（学術雑誌）, 10.1051/0004-6361/202141107

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• その他, Journal of Low Temperature Physics, Future Japanese X-ray TES Calorimeter Satellite: DIOS (Diffuse Intergalactic Oxygen Surveyor), S. Yamada; T. Ohashi; Y. Ishisaki; Y. Ezoe; N. Miyazaki; K. Kuwabara; G. Kuromaru; S. Suzuki; K. Mitsuda; N. Y. Yamasaki; Y. Takei; K. Sakai; K. Nagayoshi; R. Yamamoto; T. Hayashi; H. Muramatsu; Y. Tawara; I. Mitsuishi; Y. Babazaki; R. Nakamichi; A. Bandai; T. Yuasa; N. Ota, 2016年08月, 184, 3-4, 688, 693, 研究論文（学術雑誌）, 10.1007/s10909-015-1362-2

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• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 21pCD-11 ASTRO-H搭載 精密軟X線分光装置SXSの現状, 田代 信; 満田 和久; 山崎 典子; 竹井 洋; 辻本 匡弘; 小川 美奈; 小山 志勇; 酒井 和広; 杉田 寛之; 佐藤 洋一; 篠崎 慶亮; 岡本 篤; 藤本 龍一; 大橋 隆哉; 石崎 欣尚; 江副 祐一郎; 山田 真也; 瀬田 裕美; 寺田 幸功; 北本 俊二; 星野 晶夫; 玉川 徹; 石川 久美; 野田 博文; 佐藤 浩介; 太田 直美; 澤田 真理; 三石 郁之; 村上 正秀; 村上 弘志; 伊豫本 直子; Kelley R. L.; Kilbourne C. A.; Porter F. S.; Boyce K. R.; Eckart M. E.; Chiao M. P.; Leutenegger M. A.; Brown G. V.; McCammon D.; Szymkowiak A.; Herder J. -W. den; Haas D.; Vries C. de; Costantini E.; Akamatsu H.; Paltani S.; ASTRO-H SXSチーム, 2016年, 71, 509, 509, 10.11316/jpsgaiyo.71.1.0_509

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• 査読あり, その他, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, OXFORD UNIV PRESS, Central mass profiles of the nearby cool-core galaxy clusters Hydra A and A478, Okabe, N; Umetsu, K; Tamura, T; Fujita, Y; Takizawa, M; Matsushita, K; Fukazawa, Y; Futamase, T; Kawaharada, M; Miyazaki, S; Mochizuki, Y; Nakazawa, K; Ohashi, T; Ota, N; Sasaki, T; Sato, K; Tam, S. I, We perform aweak-lensing study of the nearby cool-core galaxy clusters, HydraA(z = 0.0538) and A478 (z = 0.0881), of which the brightest cluster galaxies (BCGs) host the powerful activities of active galactic nuclei (AGNs). For each cluster, the observed tangential shear profile is described well by either a single Navarro-Frenk-White model or a two-component model including the BCG as an unresolved point mass. For A478, we determine the BCG and its host-halo masses from a joint fit to weak-lensing and stellar photometry measurements. We find that the choice of initial mass functions (IMFs) can introduce a factor of 2 uncertainty in the BCG mass, whereas the BCG host-halo mass is constrained well by data. We perform a joint analysis of the weak-lensing and stellar kinematics data available for the Hydra A cluster, which allows us to constrain the central mass profile without assuming specific IMFs. We find that the central mass profile (r < 300 kpc) determined from the joint analysis is in excellent agreement with those from independent measurements, including dynamical masses estimated from the cold gas disc component, X-ray hydrostatic total mass estimates, and the central stella, 2016年03月11日, 456, 4, 4475, 4487, 研究論文（学術雑誌）, 10.1093/mnras/stv2916

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• 査読あり, 英語, Publications of the Astronomical Society of Japan, AGN number fraction in galaxy groups and clusters at z < 1.4 from the Subaru Hyper Suprime-Cam survey, Aoi Hashiguchi; Yoshiki Toba; Naomi Ota; Masamune Oguri; Nobuhiro Okabe; Yoshihiro Ueda; Masatoshi Imanishi; Satoshi Yamada; Tomotsugu Goto; Shuhei Koyama; Kianhong Lee; Ikuyuki Mitsuishi; Tohru Nagao; Atsushi J Nishizawa; Akatoki Noboriguchi; Taira Oogi; Koki Sakuta; Malte Schramm; Mio Shibata; Yuichi Terashima; Takuji Yamashita; Anri Yanagawa; Anje Yoshimoto, 2023年12月09日, 75, 6, 1246, 1261, 研究論文（学術雑誌）, 10.1093/pasj/psad066

  DOI URL共同研究・競争的資金等URL
• 査読あり, 英語, Astronomy & Astrophysics, The eROSITA view of the Abell 3391/95 field, Angie Veronica; Thomas H. Reiprich; Florian Pacaud; Naomi Ota; Jann Aschersleben; Veronica Biffi; Esra Bulbul; Nicolas Clerc; Klaus Dolag; Thomas Erben; Efrain Gatuzz; Vittorio Ghirardini; Jürgen Kerp; Matthias Klein; Ang Liu; Teng Liu; Konstantinos Migkas; Miriam E. Ramos-Ceja; Jeremy Sanders; Claudia Spinelli, 2024年01月, 681, A108, 研究論文（学術雑誌）, 10.1051/0004-6361/202347037

  DOI URL共同研究・競争的資金等URL
• 査読あり, 英語, Astronomy & Astrophysics, The SRG/eROSITA all-sky survey, A. Merloni; G. Lamer; T. Liu; M. E. Ramos-Ceja; H. Brunner; E. Bulbul; K. Dennerl; V. Doroshenko; M. J. Freyberg; S. Friedrich; E. Gatuzz; A. Georgakakis; F. Haberl; Z. Igo; I. Kreykenbohm; A. Liu; C. Maitra; A. Malyali; M. G. F. Mayer; K. Nandra; P. Predehl; J. Robrade; M. Salvato; J. S. Sanders; I. Stewart; D. Tubín-Arenas; P. Weber; J. Wilms; R. Arcodia; E. Artis; J. Aschersleben; A. Avakyan; C. Aydar; Y. E. Bahar; F. Balzer; W. Becker; K. Berger; T. Boller; W. Bornemann; M. Brüggen; M. Brusa; J. Buchner; V. Burwitz; F. Camilloni; N. Clerc; J. Comparat; D. Coutinho; S. Czesla; S. M. Dannhauer; L. Dauner; T. Dauser; J. Dietl; K. Dolag; T. Dwelly; K. Egg; E. Ehl; S. Freund; P. Friedrich; R. Gaida; C. Garrel; V. Ghirardini; A. Gokus; G. Grünwald; S. Grandis; I. Grotova; D. Gruen; A. Gueguen; S. Hämmerich; N. Hamaus; G. Hasinger; K. Haubner; D. Homan; J. Ider Chitham; W. M. Joseph; A. Joyce; O. König; D. M. Kaltenbrunner; A. Khokhriakova; W. Kink; C. Kirsch; M. Kluge; J. Knies; S. Krippendorf; M. Krumpe; J. Kurpas; P. Li; Z. Liu; N. Locatelli; M. Lorenz; S. Müller; E. Magaudda; C. Mannes; H. McCall; N. Meidinger; M. Michailidis; K. Migkas; D. Muñoz-Giraldo; B. Musiimenta; N. T. Nguyen-Dang; Q. Ni; A. Olechowska; N. Ota; F. Pacaud; T. Pasini; E. Perinati; A. M. Pires; C. Pommranz; G. Ponti; K. Poppenhaeger; G. Pühlhofer; A. Rau; M. Reh; T. H. Reiprich; W. Roster; S. Saeedi; A. Santangelo; M. Sasaki; J. Schmitt; P. C. Schneider; T. Schrabback; N. Schuster; A. Schwope; R. Seppi; M. M. Serim; S. Shreeram; E. Sokolova-Lapa; H. Starck; B. Stelzer; J. Stierhof; V. Suleimanov; C. Tenzer; I. Traulsen; J. Trümper; K. Tsuge; T. Urrutia; A. Veronica; S. G. H. Waddell; R. Willer; J. Wolf; M. C. H. Yeung; A. Zainab; F. Zangrandi; X. Zhang; Y. Zhang; X. Zheng, The eROSITA telescope array aboard the Spektrum Roentgen Gamma (SRG) satellite began surveying the sky in December 2019, with the aim of producing all-sky X-ray source lists and sky maps of an unprecedented depth. Here we present catalogues of both point-like and extended sources using the data acquired in the first six months of survey operations (eRASS1; completed June 2020) over the half sky whose proprietary data rights lie with the German eROSITA Consortium. We describe the observation process, the data analysis pipelines, and the characteristics of the X-ray sources. With nearly 930 000 entries detected in the most sensitive 0.2–2.3 keV energy range, the eRASS1 main catalogue presented here increases the number of known X-ray sources in the published literature by more than 60%, and provides a comprehensive inventory of all classes of X-ray celestial objects, covering a wide range of physical processes. A smaller catalogue of 5466 sources detected in the less sensitive but harder 2.3–5 keV band is the result of the first true imaging survey of the entire sky above 2 keV. We present methods to identify and flag potential spurious sources in the catalogues, which we applied for this work, and we tested and validated the astrometric accuracy via cross-comparison with other X-ray and multi-wavelength catalogues. We show that the number counts of X-ray sources in eRASSl are consistent with those derived over narrower fields by past X-ray surveys of a similar depth, and we explore the number counts variation as a function of the location in the sky. Adopting a uniform all-sky flux limit (at 50% completeness) of F_{05–2 keV} > 5 × 10⁻¹⁴ erg s⁻¹ cm⁻², we estimate that the eROSITA all-sky survey resolves into individual sources about 20% of the cosmic X-ray background in the 1–2 keV range. The catalogues presented here form part of the first data release (DR1) of the SRG/eROSITA all-sky survey. Beyond the X-ray catalogues, DR1 contains all detected and calibrated event files, source products (light curves and spectra), and all-sky maps. Illustrative examples of these are provided., 2024年01月31日, 682, A34, A34, 研究論文（学術雑誌）, 10.1051/0004-6361/202347165

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• 査読あり, 英語, The Astrophysical Journal, AGN properties of ~1 million member galaxies of galaxy groups and clusters at z < 1.4 based on the Subaru Hyper Suprime-Cam survey, Yoshiki Toba; Aoi Hashiguchi; Naomi Ota; Masamune Oguri; Nobuhiro Okabe; Yoshihiro Ueda; Masatoshi Imanishi; Atsushi J. Nishizawa; Tomotsugu Goto; Bau-Ching Hsieh; Marie Kondo; Shuhei Koyama; Kianhong Lee; Ikuyuki Mitsuishi; Tohru Nagao; Taira Oogi; Koki Sakuta; Malte Schramm; Anri Yanagawa; Anje Yoshimoto, Herein, we present the statistical properties of active galactic nuclei (AGNs) for approximately 1 million member galaxies of galaxy groups and clusters, with 0.1 $<$ cluster redshift ($z_{\rm cl}$) $<$ 1.4, selected using Subaru Hyper Suprime-Cam, the so-called CAMIRA clusters. In this research, we focused on the AGN power fraction ($f_{\rm AGN}$), which is defined as the proportion of the contribution of AGNs to the total infrared (IR) luminosity, $L_{\rm IR}$ (AGN)/$L_{\rm IR}$, and examined how $f_{\rm AGN}$ depends on (i) $z_{\rm cl}$ and (ii) the distance from the cluster center. We compiled multiwavelength data using the ultraviolet--mid-IR range. Moreover, we performed spectral energy distribution fits to determine $f_{\rm AGN}$ using the CIGALE code with the SKIRTOR AGN model. We found that (i) the value of $f_{\rm AGN}$ in the CAMIRA clusters is positively correlated with $z_{\rm cl}$, with the correlation slope being steeper than that for field galaxies, and (ii) $f_{\rm AGN}$ exhibits a high value at the cluster outskirts. These results indicate that the emergence of AGN population depends on the redshift and environment and that galaxy groups and clusters at high redshifts are important in AGN evolution. Additionally, we demonstrated that cluster--cluster mergers may enhance AGN activity at the outskirts of particularly massive galaxy clusters. Our findings are consistent with a related study on the CAMIRA clusters that was based on the AGN number fraction., 2024年02月, 研究論文（学術雑誌）, 10.48550/arXiv.2402.11188

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• 査読無し, 日本語, Jxiv, NuSTAR衛星によるRX J1347.5-1145銀河団の硬Ｘ線観測, 柴田実桜; 太田直美, 2023年11月, 426, 研究論文（その他学術会議資料等）, 10.51094/jxiv.426

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MISC

• 査読無し, 日本語, 日本天文学会年会講演予稿集, 多波長観測から迫る銀河団RXC J1053.7+5453の衝突過程と粒子加速, 板花まどか; 滝沢元和; 赤松弘規; VAN WEEREN R. J; 河原創; 深沢泰司; KAASTRA J. S; 中澤知洋; 大橋隆哉; 太田直美; ROETTGERING H. J. A; VINK J; ZANDANEL F, 2017年08月20日, 2017, 186

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」で観測した近傍銀河団・銀河群のエントロピー分布, 佐々木亨; 松下恭子; 佐藤浩介; 横田佳奈; 栗山翼; 菅野祐; 赤松弘規; 藤田裕; 中澤知洋; 岡部信広; 大橋隆哉; 太田直美; 田村隆幸; 滝沢元和, 2017年02月28日, 2017, 186

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星による銀河団RXC J1053.7+5453の温度測定, 板花まどか; 滝沢元和; 赤松弘規; VAN WEEREN R; 河原創; 深沢泰司; KAASTRA J; 中澤知洋; 大橋隆哉; 太田直美; ROETTGERING H; VINK J; ZANDANEL F, 2016年08月20日, 2016, 187

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるRXC J1053.7+5453の電波レリック周辺領域の解析, 板花まどか; 滝沢元和; 赤松弘規; VAN WEEREN R; 河原創; 深沢泰司; KAASTRA J; 河原田円; 中澤知洋; 大橋隆哉; 太田直美; ROETTGERING H; VINK J; ZANDANEL F, 2016年02月20日, 2016, 150

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, 銀河団外縁部のエントロピー異常の原因の検証, 栗山翼; 佐藤浩介; 松下恭子; 赤松弘規; 大橋隆哉; 藤田裕; 川原田円; 田村隆幸; 中澤知洋; 岡部信広; 太田直美; 滝沢元和, 2014年08月20日, 2014, 225

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• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for Very Hot/Non-Thermal Emission and Gas Bulk Motions in Clusters, 太田 直美, 2014年, 378, 381
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Exploring Gas Properties along Filaments of the Pandora's Cluster with Suzaku, 太田 直美; Ibaraki, Yukiko; Ota, Naomi; Akamatsu, Hiroki; Zhang, Yu-Ying; Finoguenov, Alexis, 2014年, 400, 401
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Entropy and pressure profiles of Abell 478 out to the virial radius with Suzaku, 太田 直美; Mochizuki, Yukiko; Matsushita, Kyoko; Sato, Kosuke; Ichikawa, Kazuya; Okabe, Nobuhiro; Sasaki, Toru; Fabian, Andy C; Walker, Stephen; Fujita, Yutaka; Tamura, Takayuki; Nakazawa, Kazuhiro; Ohashi, Takaya; Umetsu, Keiichi; Ota, Naomi; Takizawa; Motokazu, 2014年, 406, 407
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Temperature, entropy, and mass profiles to the virial radius of Abell 2199 with Suzaku, 太田 直美; Sato, Kosuke; Matsushita, Kyoko; Tamura, Takayuki; Akamatsu, Hiroki; Fukazawa, Yasushi; Fujita, Yutaka; Kawaharada, Madoka; Nakazawa, Kazuhiro; Ohashi, Takaya; Okabe, Nobuhiro; Ota, Naomi; Takizawa; Motokazu, 2014年, 414, 415
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for Very Hot/Non-Thermal Emission and Gas Bulk Motions in Clusters, OTA Naomi, 2014年, 378, 381
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Exploring Gas Properties along Filaments of the Pandora's Cluster with Suzaku, OTA Naomi; Ibaraki, Yukiko; Ota, Naomi; Akamatsu, Hiroki; Zhang, Yu-Ying; Finoguenov, Alexis, 2014年, 400, 401
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Entropy and pressure profiles of Abell 478 out to the virial radius with Suzaku, OTA Naomi; Mochizuki, Yukiko; Matsushita, Kyoko; Sato, Kosuke; Ichikawa, Kazuya; Okabe, Nobuhiro; Sasaki, Toru; Fabian, Andy C; Walker, Stephen; Fujita, Yutaka; Tamura, Takayuki; Nakazawa, Kazuhiro; Ohashi, Takaya; Umetsu, Keiichi; Ota, Naomi; Takizawa; Motokazu, 2014年, 406, 407
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Temperature, entropy, and mass profiles to the virial radius of Abell 2199 with Suzaku, OTA Naomi; Sato, Kosuke; Matsushita, Kyoko; Tamura, Takayuki; Akamatsu, Hiroki; Fukazawa, Yasushi; Fujita, Yutaka; Kawaharada, Madoka; Nakazawa, Kazuhiro; Ohashi, Takaya; Okabe, Nobuhiro; Ota, Naomi; Takizawa; Motokazu, 2014年, 414, 415
• 査読無し, その他, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for gas bulk motions in eight nearby clusters with Suzaku, OTA Naomi; Yoshida, Hiroko; Ota, Naomi, 2014年, 422, 423
• 査読無し, 日本語, 日本天文学会年会講演予稿集, Abell 2199銀河団の温度,エントロピー分布の方向依存性と鉄の分布, 佐藤浩介; 松下恭子; 大橋隆哉; 藤田裕; 川原田円; 田村隆幸; 中澤知洋; 岡部信広; 太田直美; 滝沢元和; 赤松弘規, 2012年08月20日, 2012, 219

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」衛星によるAbell 478銀河団の外縁部の観測, 望月ゆきこ; 松下恭子; 佐藤浩介; 佐藤拓也; 市川和也; 佐々木亨; FABIAN Andy. C; 藤田裕; 深沢泰司; 浜名崇; 宮崎聡; 河原田円; 田村隆幸; 中澤知洋; 大橋隆哉; 岡部信広; 梅津敬一; 太田直美; 滝沢元和, 2012年08月20日, 2012, 221

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• 査読無し, 英語, RESEARCH IN ASTRONOMY AND ASTROPHYSICS, NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES, X-ray spectroscopy of clusters of galaxies, Naomi Ota, Clusters of galaxies are the most massive objects in the Universe and precise knowledge of their mass structure is important to understand the history of structure formation and constrain still unknown types of dark contents of the Universe. X-ray spectroscopy of galaxy clusters provides rich information about the physical state of hot intracluster gas and the underlying potential structure. In this paper, starting from the basic description of clusters under equilibrium conditions, we review properties of clusters revealed primarily through X-ray observations considering their thermal and dynamical evolutions. The future prospects of cluster studies using upcoming X-ray missions are also mentioned., 2012年08月, 12, 8, 973, 994, 10.1088/1674-4527/12/8/006

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• 査読無し, 英語, RESEARCH IN ASTRONOMY AND ASTROPHYSICS, NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES, X-ray spectroscopy of clusters of galaxies, Naomi Ota, Clusters of galaxies are the most massive objects in the Universe and precise knowledge of their mass structure is important to understand the history of structure formation and constrain still unknown types of dark contents of the Universe. X-ray spectroscopy of galaxy clusters provides rich information about the physical state of hot intracluster gas and the underlying potential structure. In this paper, starting from the basic description of clusters under equilibrium conditions, we review properties of clusters revealed primarily through X-ray observations considering their thermal and dynamical evolutions. The future prospects of cluster studies using upcoming X-ray missions are also mentioned., 2012年08月, 12, 8, 973, 994, 10.1088/1674-4527/12/8/006

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, Abell2199銀河団のビリアル半径までの温度/エントロピー/質量分布, 佐藤浩介; 松下恭子; 赤松弘規; 大橋隆哉; 藤田裕; 川原田円; 田村隆幸; 中澤知洋; 岡部信広; 太田直美; 滝沢元和, 2012年02月20日, 2012, 233

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるHydra A銀河団のビリアル半径近傍までの観測 2, 佐藤拓也; 松下恭子; 佐々木亨; 佐久間絵理; 佐藤浩介; 岡部信広; 太田直美; 大橋隆哉; 滝沢元和; 川原田円; 田村隆幸; 中澤知洋; 深沢泰司; 藤田裕, 2012年02月20日, 2012, 233

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるHydra A銀河団のビリアル半径近傍までの観測 1, 佐々木亨; 佐藤拓也; 松下恭子; 佐久間絵理; 佐藤浩介; 岡部信広; 太田直美; 大橋隆哉; 滝沢元和; 川原田円; 田村隆幸; 中澤知洋; 深澤泰司; 藤田裕, 2012年02月20日, 2012, 233

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, ASTRO‐Hで視る銀河団の進化に伴う銀河団ガスの加熱と粒子加速, 川原田円; 岡部信広; 田村隆幸; 藤田裕; 滝沢元和; 松下恭子; 佐藤浩介; 太田直美; 中澤知洋; 大橋隆哉, 2012年02月20日, 2012, 89

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, X-Ray Study of the Outer Region of Abell 2142 with Suzaku, Hiroki Akamatsu; Akio Hoshino; Yoshitaka Ishisaki; Takaya Ohashi; Kosuke Sato; Yoh Takei; Naomi Ota, We observed outer regions of a bright cluster of galaxies, A 2142, with Suzaku. Temperature and brightness structures were measured out to the virial radius (r(200)) with good sensitivity. We confirmed a temperature drop from 9 keV around the cluster center to about 3.5 keV at r(200), with the density profile well approximated by the beta-model with beta = 0.85. Within 0.4r(200), the entropy profile agrees with r(1.1), as predicted by the accretion shock model. The entropy slope becomes flatter in the outer region and negative around r(200). These features suggest that the intracluster medium in the outer region is out of thermal equilibrium. Since the relaxation timescale of electron-ion Coulomb collisions is expected to be longer than the elapsed time after shock heating at r(200), one plausible reason for the low entropy is a low electron temperature compared to that of ions. Other possible explanations would be gas dumpiness, turbulence and bulk motions of the ICM. We also searched for a warm-hot intergalactic medium around r(200), and set an upper limit on the oxygen line intensity. Assuming a line-of-sight depth of 2 Mpc and oxygen abundance of 0.1 solar, the upper limit of an overdensity is calculated to be 280 or 380, depending on the foreground assumption., 2011年11月, 63, SP3, S1019, S1033, 10.1093/pasj/63.sp3.S1019

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku Observations of Iron K-Lines from the Intracluster Medium of the Coma Cluster, Takuya Sato; Kyoko Matsushita; Naomi Ota; Kosuke Sato; Kazuhiro Nakazawa; Craig L. Sarazin, The Coma cluster was observed with the X-ray Imaging Spectrometer (XIS) onboard Suzaku in six pointings, including the central X-ray peak region, 14' west offset region, 30' and 34' north west offset regions, and 44' and 60' south west offset regions. Owing to its lower background level, Suzaku has better sensitivity to Fe Ka lines than other satellites. Using precise Fe line measurements, we studied the temperature structure, possible bulk motions, and iron abundance distributions in the intracluster medium (ICM). The observed spectra were well-represented by a single-temperature model; a two- or three- temperature model did not improve chi(2) substantially. The temperature, derived from Ka line ratios of H-like and He-like Fe, agrees with those derived from the single-temperature model. Because the line ratio is a steep function of temperature, the consistency supports the accuracy of temperature measurements conducted with Suzaku. Within the 34' region, the redshift derived from the central energy of the He-like Fe line is consistent with that from optical observations, within a calibration error of 18 eV or 818 km s(-1) in the line of sight. This value is smaller than the sound velocity of the ICM, which is 1500 km s(-1). The central energy of Fe lines at the 44' offset region around the NGC 4839 subcluster is also consistent with those within the 34' region. These results on the temperature and velocity structure suggest that the core of the cluster is in a relaxed state, and non-thermal electrons relevant to the radio halo are accelerated by intracluster turbulence rather than large-scale shocks. The Fe abundance is almost constant at 0.4 solar within the 34' region, and decreases with radius. This value is slightly lower than those of other clusters, which means that the gas had been mixed well during a past merger associated with the growth of the cluster., 2011年11月, 63, SP3, S991, S1007, 10.1093/pasj/63.sp3.S991

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku Observations of Metal Distributions in the Intracluster Medium of the Centaurus Cluster, Eri Sakuma; Naomi Ota; Kosuke Sato; Takuya Sato; Kyoko Matsushita, We report the first observations of metal distributions in the intracluster medium of the Centaurus cluster up to similar to 0.17r(180) with Suzaku. Radial profiles of the O, Mg, Si, S, Ar, Ca, and Fe were determined at the outer region of the cluster, and their variations appear to be similar to each other. Within the cool core region (r < 0.045 r(180)), all of the metal distributions sharply increased toward the center. In the central region (r < 0.015 r(180)), the abundances of Si, S, Ar, Ca, and Fe were 1.5-1.8 solar, while those of O and Mg were approximately 1 solar. The derived abundance ratios of O and Mg to Fe were slightly lower than those of a set of other clusters. In contrast, the calculated mass-to-light ratios (MLRs) for O, Mg, and Fe were larger than those of the other clusters. For the outer region of the cool core (r > 0.07 r(180)), all of the abundances were almost constant at 0.5 solar. The derived MLRs were comparable to those of the other clusters. This suggests that the cD galaxy of the Centaurus cluster efficiently supplies more Fe than the other clusters., 2011年11月, 63, SP3, S979, S990, 10.1093/pasj/63.sp3.S979

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, X-Ray Study of the Outer Region of Abell 2142 with Suzaku, Hiroki Akamatsu; Akio Hoshino; Yoshitaka Ishisaki; Takaya Ohashi; Kosuke Sato; Yoh Takei; Naomi Ota, We observed outer regions of a bright cluster of galaxies, A 2142, with Suzaku. Temperature and brightness structures were measured out to the virial radius (r(200)) with good sensitivity. We confirmed a temperature drop from 9 keV around the cluster center to about 3.5 keV at r(200), with the density profile well approximated by the beta-model with beta = 0.85. Within 0.4r(200), the entropy profile agrees with r(1.1), as predicted by the accretion shock model. The entropy slope becomes flatter in the outer region and negative around r(200). These features suggest that the intracluster medium in the outer region is out of thermal equilibrium. Since the relaxation timescale of electron-ion Coulomb collisions is expected to be longer than the elapsed time after shock heating at r(200), one plausible reason for the low entropy is a low electron temperature compared to that of ions. Other possible explanations would be gas dumpiness, turbulence and bulk motions of the ICM. We also searched for a warm-hot intergalactic medium around r(200), and set an upper limit on the oxygen line intensity. Assuming a line-of-sight depth of 2 Mpc and oxygen abundance of 0.1 solar, the upper limit of an overdensity is calculated to be 280 or 380, depending on the foreground assumption., 2011年11月, 63, SP3, S1019, S1033, 10.1093/pasj/63.sp3.S1019

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku Observations of Iron K-Lines from the Intracluster Medium of the Coma Cluster, Takuya Sato; Kyoko Matsushita; Naomi Ota; Kosuke Sato; Kazuhiro Nakazawa; Craig L. Sarazin, The Coma cluster was observed with the X-ray Imaging Spectrometer (XIS) onboard Suzaku in six pointings, including the central X-ray peak region, 14' west offset region, 30' and 34' north west offset regions, and 44' and 60' south west offset regions. Owing to its lower background level, Suzaku has better sensitivity to Fe Ka lines than other satellites. Using precise Fe line measurements, we studied the temperature structure, possible bulk motions, and iron abundance distributions in the intracluster medium (ICM). The observed spectra were well-represented by a single-temperature model; a two- or three- temperature model did not improve chi(2) substantially. The temperature, derived from Ka line ratios of H-like and He-like Fe, agrees with those derived from the single-temperature model. Because the line ratio is a steep function of temperature, the consistency supports the accuracy of temperature measurements conducted with Suzaku. Within the 34' region, the redshift derived from the central energy of the He-like Fe line is consistent with that from optical observations, within a calibration error of 18 eV or 818 km s(-1) in the line of sight. This value is smaller than the sound velocity of the ICM, which is 1500 km s(-1). The central energy of Fe lines at the 44' offset region around the NGC 4839 subcluster is also consistent with those within the 34' region. These results on the temperature and velocity structure suggest that the core of the cluster is in a relaxed state, and non-thermal electrons relevant to the radio halo are accelerated by intracluster turbulence rather than large-scale shocks. The Fe abundance is almost constant at 0.4 solar within the 34' region, and decreases with radius. This value is slightly lower than those of other clusters, which means that the gas had been mixed well during a past merger associated with the growth of the cluster., 2011年11月, 63, SP3, S991, S1007, 10.1093/pasj/63.sp3.S991

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku Observations of Metal Distributions in the Intracluster Medium of the Centaurus Cluster, Eri Sakuma; Naomi Ota; Kosuke Sato; Takuya Sato; Kyoko Matsushita, We report the first observations of metal distributions in the intracluster medium of the Centaurus cluster up to similar to 0.17r(180) with Suzaku. Radial profiles of the O, Mg, Si, S, Ar, Ca, and Fe were determined at the outer region of the cluster, and their variations appear to be similar to each other. Within the cool core region (r < 0.045 r(180)), all of the metal distributions sharply increased toward the center. In the central region (r < 0.015 r(180)), the abundances of Si, S, Ar, Ca, and Fe were 1.5-1.8 solar, while those of O and Mg were approximately 1 solar. The derived abundance ratios of O and Mg to Fe were slightly lower than those of a set of other clusters. In contrast, the calculated mass-to-light ratios (MLRs) for O, Mg, and Fe were larger than those of the other clusters. For the outer region of the cool core (r > 0.07 r(180)), all of the abundances were almost constant at 0.5 solar. The derived MLRs were comparable to those of the other clusters. This suggests that the cD galaxy of the Centaurus cluster efficiently supplies more Fe than the other clusters., 2011年11月, 63, SP3, S979, S990, 10.1093/pasj/63.sp3.S979

  DOI URL
• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」衛星によるAbell 1835銀河団の外縁部の研究, 市川和也; 松下恭子; 佐藤浩介; 岡部信広; 梅津敬一; 太田直美; 大橋隆哉; 川原田円; 田村隆幸; 滝沢元和; 中澤知洋; 深沢泰司; 藤田裕, 2011年08月20日, 2011, 226

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星による中規模銀河団Hydra‐Aのビリアル半径までの観測, 佐藤拓也; 松下恭子; 佐藤浩介; 岡部信広; 梅津敬一; 太田直美; 大橋隆哉; 滝沢元和; 川原田円; 田村隆幸; 中澤知洋; 深沢泰司; 藤田裕, 2011年08月20日, 2011, 228

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるHydra‐A clusterのビリアル半径近傍の周辺環境, 佐藤拓也; 松下恭子; 岡部信広; 梅津敬一; 太田直美; 大橋隆哉; 佐藤浩介; 滝沢元和; 川原田円; 田村隆幸; 中澤知洋; 深沢泰司; 藤田裕, 2011年02月20日, 2011, 186

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」衛星によるAbell 1835銀河団の外縁部の研究, 市川和也; 松下恭子; 岡部信広; 梅津敬一; 太田直美; 大橋隆哉; 川原田円; 田村隆幸; 佐藤浩介; 滝沢元和; 中澤知洋; 深沢泰司; 藤田裕, 2011年02月20日, 2011, 186

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• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, Suzaku observations of X-ray excess emission in the cluster of galaxies A3112, T. Lehto; J. Nevalainen; M. Bonamente; N. Ota; J. Kaastra, Aims. We analysed the Suzaku XIS1 data of the A3112 cluster of galaxies in order to examine the X-ray excess emission in this cluster reported earlier with the XMM-Newton and Chandra satellites. Methods. We performed X-ray spectroscopy on the data of a single large region. We carried out simulations to estimate the systematic uncertainties affecting the X-ray excess signal. Results. The best-fit temperature of the intracluster gas depends strongly on the choice of the energy band used for the spectral analysis. This proves the existence of excess emission component in addition to the single-temperature MEKAL in A3112. We showed that this effect is not an artifact due to uncertainties of the background modeling, instrument calibration or the amount of Galactic absorption. Neither does the PSF scatter of the emission from the cool core nor the projection of the cool gas in the cluster outskirts produce the effect. Finally we modeled the excess emission either by using an additional MEKAL or powerlaw component. Due to the small differencies between thermal and non-thermal model we can not rule out the non-thermal origin of the excess emission based on the goodness of the fit. Assuming that it has a thermal origin, we further examined the differential emission measure (DEM) models. We utilised two different DEM models, a Gaussian differential emission measure distribution (GDEM) and WDEM model, where the emission measure of a number of thermal components is distributed as a truncated power law. The best-fit XIS1 MEKAL temperature for the 0.4-7.0 keV band is 4.7 +/- 0.1 keV, consistent with that obtained using GDEM and WDEM models., 2010年12月, 524, 10.1051/0004-6361/201014508

  DOI URL
• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, Suzaku observations of X-ray excess emission in the cluster of galaxies A3112, T. Lehto; J. Nevalainen; M. Bonamente; N. Ota; J. Kaastra, Aims. We analysed the Suzaku XIS1 data of the A3112 cluster of galaxies in order to examine the X-ray excess emission in this cluster reported earlier with the XMM-Newton and Chandra satellites. Methods. We performed X-ray spectroscopy on the data of a single large region. We carried out simulations to estimate the systematic uncertainties affecting the X-ray excess signal. Results. The best-fit temperature of the intracluster gas depends strongly on the choice of the energy band used for the spectral analysis. This proves the existence of excess emission component in addition to the single-temperature MEKAL in A3112. We showed that this effect is not an artifact due to uncertainties of the background modeling, instrument calibration or the amount of Galactic absorption. Neither does the PSF scatter of the emission from the cool core nor the projection of the cool gas in the cluster outskirts produce the effect. Finally we modeled the excess emission either by using an additional MEKAL or powerlaw component. Due to the small differencies between thermal and non-thermal model we can not rule out the non-thermal origin of the excess emission based on the goodness of the fit. Assuming that it has a thermal origin, we further examined the differential emission measure (DEM) models. We utilised two different DEM models, a Gaussian differential emission measure distribution (GDEM) and WDEM model, where the emission measure of a number of thermal components is distributed as a truncated power law. The best-fit XIS1 MEKAL temperature for the 0.4-7.0 keV band is 4.7 +/- 0.1 keV, consistent with that obtained using GDEM and WDEM models., 2010年12月, 524, 10.1051/0004-6361/201014508

  DOI URL
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, IMPACT OF CHANDRA CALIBRATION UNCERTAINTIES ON GALAXY CLUSTER TEMPERATURES: APPLICATION TO THE HUBBLE CONSTANT, Erik D. Reese; Hajime Kawahara; Tetsu Kitayama; Naomi Ota; Shin Sasaki; Yasushi Suto, We perform a uniform, systematic X-ray spectroscopic analysis of a sample of 38 galaxy clusters with three different Chandra calibrations. The temperatures change systematically between calibrations. Cluster temperatures change on average by roughly similar to 6% for the smallest changes and roughly similar to 13% for the more extreme changes between calibrations. We explore the effects of the Chandra calibration on cluster spectral properties and the implications on Sunyaev-Zel'dovich effect (SZE) and X-ray determinations of the Hubble constant. The Hubble parameter changes by +10% and -13% between the current calibration and two previous Chandra calibrations, indicating that changes in the cluster temperature basically explain the entire change in H-0. Although this work focuses on the difference in spectral properties and resultant Hubble parameters between the calibrations, it is intriguing to note that the newer calibrations favor a lower value of the Hubble constant, H-0 similar to 60 km s(-1) Mpc(-1), typical of results from SZE/X-ray distances. Both galaxy clusters themselves and the details of the instruments must be known precisely to enable reliable precision cosmology with clusters, which will be feasible with combined efforts from ongoing observations and planned missions and observatories covering a wide range of wavelengths., 2010年09月, 721, 1, 653, 669, 10.1088/0004-637X/721/1/653

  DOI URL
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, IMPACT OF CHANDRA CALIBRATION UNCERTAINTIES ON GALAXY CLUSTER TEMPERATURES: APPLICATION TO THE HUBBLE CONSTANT, Erik D. Reese; Hajime Kawahara; Tetsu Kitayama; Naomi Ota; Shin Sasaki; Yasushi Suto, We perform a uniform, systematic X-ray spectroscopic analysis of a sample of 38 galaxy clusters with three different Chandra calibrations. The temperatures change systematically between calibrations. Cluster temperatures change on average by roughly similar to 6% for the smallest changes and roughly similar to 13% for the more extreme changes between calibrations. We explore the effects of the Chandra calibration on cluster spectral properties and the implications on Sunyaev-Zel'dovich effect (SZE) and X-ray determinations of the Hubble constant. The Hubble parameter changes by +10% and -13% between the current calibration and two previous Chandra calibrations, indicating that changes in the cluster temperature basically explain the entire change in H-0. Although this work focuses on the difference in spectral properties and resultant Hubble parameters between the calibrations, it is intriguing to note that the newer calibrations favor a lower value of the Hubble constant, H-0 similar to 60 km s(-1) Mpc(-1), typical of results from SZE/X-ray distances. Both galaxy clusters themselves and the details of the instruments must be known precisely to enable reliable precision cosmology with clusters, which will be feasible with combined efforts from ongoing observations and planned missions and observatories covering a wide range of wavelengths., 2010年09月, 721, 1, 653, 669, 10.1088/0004-637X/721/1/653

  DOI URL
• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星による高温銀河団A2163からの硬X線放射の検出, 太田直美; PRATT G.W; 北山哲; 大島泰; 松尾宏; 坪井昌人; REIPRICH T.H, 2010年08月20日, 2010, 180

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• 査読無し, その他, Proceedings of SPIE - The International Society for Optical Engineering, The ASTRO-H mission, Tadayuki Takahashi; Kazuhisa Mitsuda; Richard Kelley; Felix Aharonian; Fumie Akimoto; Steve Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Hisamitsu Awaki; Aya Bamba; Nobutaka Bando; Mark Bautz; Roger Blandford; Kevin Boyce; Greg Brown; Maria Chernyakova; Paolo Coppi; Elisa Costantini; Jean Cottam; John Crow; Jelle De Plaa; Cor De Vries; Jan Willem Den Herder; Michael DiPirro; Chris Done; Tadayasu Dotani; Ken Ebisawa; Teruaki Enoto; Yuichiro Ezoe; Andrew Fabian; Ryuichi Fujimoto; Yasushi Fukazawa; Stefan Funk; Akihiro Furuzawa; Massimiliano Galeazzi; Poshak Gandhi; Keith Gendreau; Kirk Gilmore; Yoshito Haba; Kenji Hamaguchi; Isamu Hatsukade; Kiyoshi Hayashida; Junko Hiraga; Kazuyuki Hirose; Ann Hornschemeier; John Hughes; Una Hwang; Ryo Iizuka; Kazunori Ishibashi; Manabu Ishida; Kosei Ishimura; Yoshitaka Ishisaki; Naoki Isobe; Masayuki Ito; Naoko Iwata; Jelle Kaastra; Timothy Kallman; Tuneyoshi Kamae; Hideaki Katagiri; Jun Kataoka; Satoru Katsuda; Madoka Kawaharada; Nobuyuki Kawai; Shigeo Kawasaki; Dmitry Khangaluyan; Caroline Kilbourne; Kenzo Kinugasa; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Tatsuro Kosaka; Taro Kotani; Katsuji Koyama; Aya Kubota; Hideyo Kunieda; Philippe Laurent; François Lebrun; Olivier Limousin; Michael Loewenstein; Knox Long; Grzegorz Madejski; Yoshitomo Maeda; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Jon Miller; Shin Mineshige; Kenji Minesugi; Takuya Miyazawa; Tsunefumi Mizuno; Koji Mori; Hideyuki Mori; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky, © 2010 SPIE. The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe by performing high-resolution, high-throughput spectroscopy with moderate angular resolution. ASTRO-H covers very wide energy range from 0.3 keV to 600 keV. ASTRO-H allows a combination of wide band X-ray spectroscopy (5-80 keV) provided by multilayer coating, focusing hard X-ray mirrors and hard X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3-12 keV) provided by thin-foil X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD camera as a focal plane detector for a soft X-ray telescope (0.4-12 keV) and a non-focusing soft gamma-ray detector (40-600 keV). The micro-calorimeter system is developed by an international collaboration led by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with high spectral resolution of ΔE ~7 eV provided by the micro-calorimeter will enable a wide variety of important science themes to be pursued., 2010年, 7732, 77320Z-77320Z-18, 10.1117/12.857875

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• 査読無し, 英語, SPACE TELESCOPES AND INSTRUMENTATION 2010: ULTRAVIOLET TO GAMMA RAY, SPIE-INT SOC OPTICAL ENGINEERING, The ASTRO-H Mission, Tadayuki Takahashi; Kazuhisa Mitsuda; Richard Kelley; Felix Aharonian; Fumie Akimoto; Steve Allen; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Hisamitsu Awaki; Aya Bamba; Nobutaka Bando; Mark Bautz; Roger Blandford; Kevin Boyce; Greg Brown; Maria Chernyakova; Paolo Coppi; Elisa Costantini; Jean Cottam; John Crow; Jelle de Plaa; Cor de Vries; Jan-Willem den Herder; Michael DiPirro; Chris Done; Tadayasu Dotani; Ken Ebisawa; Teruaki Enoto; Yuichiro Ezoe; Andrew Fabian; Ryuichi Fujimoto; Yasushi Fukazawa; Stefan Funk; Akihiro Furuzawa; Massimiliano Galeazzi; Poshak Gandhi; Keith Gendreau; Kirk Gilmore; Yoshito Haba; Kenji Hamaguchi; Isamu Hatsukade; Kiyoshi Hayashida; J. Hiraga; Kazuyuki Hirose; Ann Hornschemeier; John Hughes; Una Hwang; Ryo Iizuka; Kazunori Ishibashi; Manabu Ishida; Kosei Ishimura; Yoshitaka Ishisaki; Naoki Isobe; Masayuki Ito; Naoko Iwata; Jelle Kaastra; Timothy Kallman; Tuneyoshi Kamae; Hideaki Katagiri; Jun Kataoka; Satoru Katsuda; Madoka Kawaharada; Nobuyuki Kawai; Shigeo Kawasaki; Dmitry Khangaluyan; Caroline Kilbourne; Kenzo Kinugasa; Shunji Kitamoto; Tetsu Kitayama; Takayoshi Kohmura; Motohide Kokubun; Tatsuro Kosaka; Taro Kotani; Katsuji Koyama; Aya Kubota; Hideyo Kunieda; Philippe Laurent; Francois Lebrun; Olivier Limousin; Michael Loewenstein; Knox Long; Grzegorz Madejski; Yoshitomo Maeda; Kazuo Makishima; Maxim Markevitch; Hironori Matsumoto; Kyoko Matsushita; Dan McCammon; Jon Miller; Shin Mineshige; Kenji Minesugi; Takuya Miyazawa; Tsunefumi Mizuno; Koji Mori; Hideyuki Mori; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky; Yujin Nakagawa; Takao Nakagawa; Hiroshi Nakajima; Takeshi Nakamori; Kazuhiro Nakazawa; Yoshiharu Namba; Masaharu Nomachi; Steve O' Dell; Hiroyuki Ogawa; Mina Ogawa; Keiji Ogi; Takaya Ohashi; Masanori Ohno; Masayuki Ohta; Takashi Okajima; Naomi Ota; Masanobu Ozaki; Frits Paerels; Stephane Paltani; Arvind Parmer; Robert Petre; Martin Pohl; Scott Porter; Brian Ramsey; Christopher Reynolds; Shin-ichiro Sakai; Rita Sambruna; Goro Sato; Yoichi Sato; Peter Serlemitsos; Maki Shida; Takanobu Shimada; Keisuke Shinozaki; Peter Shirron; Randall Smith; Gary Sneiderman; Yang Soong; Lukasz Stawarz; Hiroyuki Sugita; Andrew Szymkowiak; Hiroyasu Tajima; Hiromitsu Takahashi; Yoh Takei; Toru Tamagawa; Takayuki Tamura; Keisuke Tamura; Takaaki Tanaka; Yasuo Tanaka; Yasuyuki Tanaka; Makoto Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Francesco Tombesi; Hiroshi Tomida; Miyako Tozuka; Yoko Tsuboi; Masahiro Tsujimoto; Hiroshi Tsunemi; Takeshi Tsuru; Hiroyuki Uchida; Yasunobu Uchiyama; Hideki Uchiyama; Yoshihiro Ueda; Shinichiro Uno; Meg Urry; Shin Watanabe; Nicholas White; Takahiro Yamada; Hiroya Yamaguchi; Kazutaka Yamaoka; Noriko Yamasaki; Makoto Yamauchi; Shigeo Yamauchi; Yoichi Yatsu; Daisuke Yonetoku; Atsumasa Yoshida, The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe by performing high-resolution, high-throughput spectroscopy with moderate angular resolution. ASTRO-H covers very wide energy range from 0.3 keV to 600 keV. ASTRO-H allows a combination of wide band X-ray spectroscopy (5-80 keV) provided by multilayer coating, focusing hard X-ray mirrors and hard X-ray imaging detectors, and high energy-resolution soft X-ray spectroscopy (0.3-12 keV) provided by thin-foil X-ray optics and a micro-calorimeter array. The mission will also carry an X-ray CCD camera as a focal plane detector for a soft X-ray telescope (0.4-12 keV) and a non-focusing soft gamma-ray detector (40-600 keV). The micro-calorimeter system is developed by an international collaboration led by ISAS/JAXA and NASA. The simultaneous broad bandpass, coupled with high spectral resolution of Delta E similar to 7 eV provided by the micro-calorimeter will enable a wide variety of important science themes to be pursued., 2010年, 7732, 77320Z-77320Z-18, 10.1117/12.857875

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• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, X-RAY DIAGNOSTICS OF THERMAL CONDITIONS OF THE HOT PLASMAS IN THE CENTAURUS CLUSTER, I. Takahashi; M. Kawaharada; K. Makishima; K. Matsushita; Y. Fukazawa; Y. Ikebe; T. Kitaguchi; M. Kokubun; K. Nakazawa; S. Okuyama; N. Ota; T. Tamura, X-ray data of the Centaurus cluster, obtained with XMM-Newton for 45 ks, were analyzed. Deprojected EPIC spectra from concentric thin-shell regions were reproduced equally well by a single-phase plasma emission model, or by a two-phase model developed by ASCA, both incorporating cool (1.7-2.0 keV) and hot (similar to 4 keV) plasma temperatures. However, EPIC spectra with higher statistics, accumulated over three-dimensional thick-shell regions, were reproduced better by the two-phase model than by the singe-phase one. Therefore, hot and cool plasma phases are inferred to co-exist in the cluster core region within similar to 70 kpc. The iron and silicon abundances of the plasma were reconfirmed to increase significantly toward the center, while that of oxygen was consistent with being radially constant. The implied nonsolar abundance ratios explain away the previously reported excess X-ray absorption from the central region. Although an additional cool (similar to 0.7 keV) emission was detected within similar to 20 kpc of the center, the RGS data gave tight upper limits on any emission with temperatures below similar to 0.5 keV. These results are compiled into a magnetosphere model, which interprets the cool phase as confined within closed magnetic loops anchored to the cD galaxy. When combined with the so-called Rosner-Tucker-Vaiana mechanism which applies to solar coronae, this model can potentially explain basic properties of the cool phase, including its temperature and thermal stability., 2009年08月, 701, 1, 377, 395, 10.1088/0004-637X/701/1/377

  DOI URL
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, X-RAY DIAGNOSTICS OF THERMAL CONDITIONS OF THE HOT PLASMAS IN THE CENTAURUS CLUSTER, I. Takahashi; M. Kawaharada; K. Makishima; K. Matsushita; Y. Fukazawa; Y. Ikebe; T. Kitaguchi; M. Kokubun; K. Nakazawa; S. Okuyama; N. Ota; T. Tamura, X-ray data of the Centaurus cluster, obtained with XMM-Newton for 45 ks, were analyzed. Deprojected EPIC spectra from concentric thin-shell regions were reproduced equally well by a single-phase plasma emission model, or by a two-phase model developed by ASCA, both incorporating cool (1.7-2.0 keV) and hot (similar to 4 keV) plasma temperatures. However, EPIC spectra with higher statistics, accumulated over three-dimensional thick-shell regions, were reproduced better by the two-phase model than by the singe-phase one. Therefore, hot and cool plasma phases are inferred to co-exist in the cluster core region within similar to 70 kpc. The iron and silicon abundances of the plasma were reconfirmed to increase significantly toward the center, while that of oxygen was consistent with being radially constant. The implied nonsolar abundance ratios explain away the previously reported excess X-ray absorption from the central region. Although an additional cool (similar to 0.7 keV) emission was detected within similar to 20 kpc of the center, the RGS data gave tight upper limits on any emission with temperatures below similar to 0.5 keV. These results are compiled into a magnetosphere model, which interprets the cool phase as confined within closed magnetic loops anchored to the cD galaxy. When combined with the so-called Rosner-Tucker-Vaiana mechanism which applies to solar coronae, this model can potentially explain basic properties of the cool phase, including its temperature and thermal stability., 2009年08月, 701, 1, 377, 395, 10.1088/0004-637X/701/1/377

  DOI URL
• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, Suzaku measurement of Abell 2204's intracluster gas temperature profile out to 1800 kpc (Research Note), T. H. Reiprich; D. S. Hudson; Y. -Y. Zhang; K. Sato; Y. Ishisaki; A. Hoshino; T. Ohashi; N. Ota; Y. Fujita, Context. Measurements of intracluster gas temperatures out to large radii, where much of the galaxy cluster mass resides, are important for using clusters for precision cosmology and for studies of cluster physics. Previous attempts to measure robust temperatures at cluster virial radii have failed. Aims. The goal of this work is to measure the temperature profile of the very relaxed symmetric galaxy cluster Abell 2204 out to large radii, possibly reaching the virial radius. Methods. Taking advantage of its low particle background due to its low-Earth orbit, Suzaku data are used to measure the outer temperature profile of Abell 2204. These data are combined with Chandra and XMM-Newton data of the same cluster to make the connection to the inner regions, unresolved by Suzaku, and to determine the smearing due to Suzaku's point spread function. Results. The temperature profile of Abell 2204 is determined from similar to 10 kpc to similar to 1800 kpc, close to an estimate of r(200) ( the approximation to the virial radius). The temperature rises steeply from below 4 keV in the very center up to more than 8 keV in the intermediate range and then decreases again to about 4 keV at the largest radii. Varying the measured particle background normalization artificially by +/- 10% does not change the results significantly. Several additional systematic effects are quantified, e. g., those due to the point spread function and astrophysical fore- and backgrounds. Predictions for outer temperature profiles based on hydrodynamic simulations show good agreement. In particular, we find the observed temperature profile to be slightly steeper but consistent with a drop of a factor of 0.6 from 0.3 r(200) to r(200), as predicted by simulations. Conclusions. Intracluster gas temperature measurements up to r(200) seem feasible with Suzaku, after a careful analysis of the different background components and the effects of the point spread function. Such measurements now need to be performed for a statistical sample of clusters. The result obtained here indicates that numerical simulations capture the intracluster gas physics well in cluster outskirts., 2009年07月, 501, 3, 899, 905, 10.1051/0004-6361/200810404

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• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, Suzaku measurement of Abell 2204's intracluster gas temperature profile out to 1800 kpc (Research Note), T. H. Reiprich; D. S. Hudson; Y. -Y. Zhang; K. Sato; Y. Ishisaki; A. Hoshino; T. Ohashi; N. Ota; Y. Fujita, Context. Measurements of intracluster gas temperatures out to large radii, where much of the galaxy cluster mass resides, are important for using clusters for precision cosmology and for studies of cluster physics. Previous attempts to measure robust temperatures at cluster virial radii have failed. Aims. The goal of this work is to measure the temperature profile of the very relaxed symmetric galaxy cluster Abell 2204 out to large radii, possibly reaching the virial radius. Methods. Taking advantage of its low particle background due to its low-Earth orbit, Suzaku data are used to measure the outer temperature profile of Abell 2204. These data are combined with Chandra and XMM-Newton data of the same cluster to make the connection to the inner regions, unresolved by Suzaku, and to determine the smearing due to Suzaku's point spread function. Results. The temperature profile of Abell 2204 is determined from similar to 10 kpc to similar to 1800 kpc, close to an estimate of r(200) ( the approximation to the virial radius). The temperature rises steeply from below 4 keV in the very center up to more than 8 keV in the intermediate range and then decreases again to about 4 keV at the largest radii. Varying the measured particle background normalization artificially by +/- 10% does not change the results significantly. Several additional systematic effects are quantified, e. g., those due to the point spread function and astrophysical fore- and backgrounds. Predictions for outer temperature profiles based on hydrodynamic simulations show good agreement. In particular, we find the observed temperature profile to be slightly steeper but consistent with a drop of a factor of 0.6 from 0.3 r(200) to r(200), as predicted by simulations. Conclusions. Intracluster gas temperature measurements up to r(200) seem feasible with Suzaku, after a careful analysis of the different background components and the effects of the point spread function. Such measurements now need to be performed for a statistical sample of clusters. The result obtained here indicates that numerical simulations capture the intracluster gas physics well in cluster outskirts., 2009年07月, 501, 3, 899, 905, 10.1051/0004-6361/200810404

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• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, CONSTRAINTS ON THE INTRACLUSTER DUST EMISSION IN THE COMA CLUSTER OF GALAXIES, Tetsu Kitayama; Yuichi Ito; Yoko Okada; Hidehiro Kaneda; Hidenori Takahashi; Naomi Ota; Takashi Onaka; Yuka Y. Tajiri; Hirohisa Nagata; Kenkichi Yamada, We have undertaken a search for the infrared emission from the intracluster dust in the Coma cluster of galaxies by the Multiband Imaging Photometer for Spitzer. Our observations yield the deepest mid and far-infrared images of a galaxy cluster ever achieved. In each of the three bands, we have not detected a signature of the central excess component in contrast to the previous report on the detection by Infrared Space Observatory (ISO). We still find that the brightness ratio between 70 mu m and 160 mu m shows a marginal sign of the central excess, in qualitative agreement with the ISO result. Our analysis suggests that the excess ratio is more likely due to faint infrared sources lying on fluctuating cirrus foreground. Our observations yield the 2 sigma upper limits on the excess emission within 100 kpc of the cluster center as 5 x 10(-3) MJy sr(-1), 6 x 10(-2) MJy sr(-1), and 7 x 10(-2) MJy sr(-1), at 24, 70, and 160 mu m, respectively. These values are in agreement with those found in other galaxy clusters and suggest that dust is deficient near the cluster center by more than 3 orders of magnitude compared with the interstellar medium., 2009年04月, 695, 2, 1191, 1198, 10.1088/0004-637X/695/2/1191

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• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, CONSTRAINTS ON THE INTRACLUSTER DUST EMISSION IN THE COMA CLUSTER OF GALAXIES, Tetsu Kitayama; Yuichi Ito; Yoko Okada; Hidehiro Kaneda; Hidenori Takahashi; Naomi Ota; Takashi Onaka; Yuka Y. Tajiri; Hirohisa Nagata; Kenkichi Yamada, We have undertaken a search for the infrared emission from the intracluster dust in the Coma cluster of galaxies by the Multiband Imaging Photometer for Spitzer. Our observations yield the deepest mid and far-infrared images of a galaxy cluster ever achieved. In each of the three bands, we have not detected a signature of the central excess component in contrast to the previous report on the detection by Infrared Space Observatory (ISO). We still find that the brightness ratio between 70 mu m and 160 mu m shows a marginal sign of the central excess, in qualitative agreement with the ISO result. Our analysis suggests that the excess ratio is more likely due to faint infrared sources lying on fluctuating cirrus foreground. Our observations yield the 2 sigma upper limits on the excess emission within 100 kpc of the cluster center as 5 x 10(-3) MJy sr(-1), 6 x 10(-2) MJy sr(-1), and 7 x 10(-2) MJy sr(-1), at 24, 70, and 160 mu m, respectively. These values are in agreement with those found in other galaxy clusters and suggest that dust is deficient near the cluster center by more than 3 orders of magnitude compared with the interstellar medium., 2009年04月, 695, 2, 1191, 1198, 10.1088/0004-637X/695/2/1191

  DOI URL
• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」によるMS1512.4+3647銀河団プラズマの重元素組成の研究, 川原田円; 北口貴雄; 中澤知洋; 牧島一夫; 山崎典子; 太田直美; 深沢泰司; 松下恭子; 佐藤浩介; 大橋隆哉, 2009年02月20日, 2009, 198

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Constraint of Non-Thermal X-Ray Emission from the On-Going Merger Cluster Abell 3376 with Suzaku, Naomi Kawano; Yasushi Fukazawa; Sho Nishino; Kazuhiro Nakazawa; Takao Kitaguchi; Kazuo Makishima; Tadayuki Takahashi; Motohide Kokubun; Naomi Ota; Takaya Ohashi; Naoki Isobe; J. Patrick Henry; Ann Hornschemeier, Clusters of galaxies are among the best candidates for particle acceleration sources in the universe, a signature of which is non-thermal hard X-ray emission from the accelerated relativistic particles. We present early results on Suzaku observations of non-thermal emission from Abell 3376, which is a nearby on-going merger cluster. Suzaku observed the cluster twice, while focusing on the cluster center containing the diffuse radio emission to the east, and a cluster peripheral region to the west. For both observations, we detected no excess hard X-ray emission above the thermal cluster emission. An upper limit on the non-thermal X-ray flux of 2.1 x 10-(11) erg cm(-2) s(-1) (15-50 keV) at the 3 sigma level from a 34' x 34' region, derived with the Hard X-ray Detector (HXD), is similar to that obtained with the BeppoSAX/PDS. Using the X-ray Imaging Spectrometer (XIS) data, the upper limit on the non-thermal emission from the West Relic is independently constrained to be < 1.1 x 10(-12) ergs(-1) cm(-2) (4-8 keV) at the 3 sigma level from a 122 arcmin(2) region. Assuming Compton scattering between relativistic particles and the cosmic microwave background photons, the intracluster magnetic field B is limited to be > 0.03 mu G (HXD) and > 0.10 mu G (XIS)., 2009年01月, 61, S377, S386, 10.1093/pasj/61.sp1.S377

  DOI URL
• 査読無し, その他, Publications of the Astronomical Society of Japan, Constraint of Non-Thermal X-Ray Emission from the On-Going Merger Cluster Abell 3376 with Suzaku, OTA Naomi; Kawano, N; Fukazawa, Y; Nishino, S; Nakazawa, K; Kitaguchi, T; Makishima, K; Takahashi, T; Kokubun, M; Ota, N; Ohashi, T; Isobe, N; Henry, J. P; Hornschemeier, A, 2009年, 61, S377-S386
• 査読無し, 英語, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, WILEY-BLACKWELL, A bright, dust-obscured, millimetre-selected galaxy beyond the Bullet Cluster (1E0657-56), G. W. Wilson; D. H. Hughes; I. Aretxaga; H. Ezawa; J. E. Austermann; S. Doyle; D. Ferrusca; I. Hernandez-Curiel; R. Kawabe; T. Kitayama; K. Kohno; A. Kuboi; H. Matsuo; P. D. Mauskopf; Y. Murakoshi; A. Montana; P. Natarajan; T. Oshima; N. Ota; T. A. Perera; J. Rand; K. S. Scott; K. Tanaka; M. Tsuboi; C. C. Williams; N. Yamaguchi; M. S. Yun, Deep 1.1 mm continuum observations of 1E0657-56 (the 'Bullet Cluster') taken with the millimeter-wavelength camera AzTEC on the 10-m Atacama Submillimeter Telescope Experiment (ASTE), have revealed an extremely bright (S(1.1 mm) = 15.9 mJy) unresolved source. This source, MMJ065837-5557.0, lies close to a maximum in the density of underlying mass distribution, towards the larger of the two interacting clusters as traced by the weak-lensing analysis of Clowe et al. Using optical-infrared (IR) colours, we argue that MMJ065837-5557.0 lies at a redshift of z = 2.7 +/- 2. A lensing-derived mass model for the Bullet Cluster shows a critical line (caustic) of magnification within a few arcsec of the AzTEC source, sufficient to amplify the intrinsic millimetre-wavelength flux of the AzTEC galaxy by a factor of > 20. After subtraction of the foreground cluster emission at 1.1 mm due to the Sunyaev-Zel'dovich effect, and correcting for the magnification, the rest-frame far-IR luminosity of MMJ065837-5557.0 is <= 10(12) L(circle dot), characteristic of a luminous infrared galaxy (LIRG). We explore various scenarios to explain the colours, morphologies and positional offsets between the potential optical and IR counterparts, and their relationship with MMJ065837-5557.0. Until higher resolution and more sensitive (sub)millimetre observations are available, the detection of background galaxies close to the caustics of massive lensing clusters offers the only opportunity to study this intrinsically faint millimetre-galaxy population., 2008年11月, 390, 3, 1061, 1070, 10.1111/j.1365-2966.2008.13774.x

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• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, Suzaku broad-band spectroscopy of RX J1347.5-1145: constraints on the extremely hot gas and non-thermal emission, N. Ota; K. Murase; T. Kitayama; E. Komatsu; M. Hattori; H. Matsuo; T. Oshima; Y. Suto; K. Yoshikawa, Context. We present the results of our analysis of long Suzaku observations (149 ks and 122 ks for XIS and HXD, respectively) of the most X-ray luminous galaxy cluster, RX J1347.5-1145, at z = 0.451. Aims. To understand the gas physics of a violent, cluster merger, we study physical properties of the hot (similar to 20 keV) gas clump in the south-east ( SE) region discovered previously by Sunyaev-Zel'dovich (SZ) effect observations. Using hard X-ray data, a signature of non-thermal emission is also explored. Methods. We perform single as well as multi-temperature fits to the Suzaku XIS spectra. The Suzaku XIS and HXD, and the Chandra ACIS-I data are then combined to examine the properties of the hot gas component in the SE region. We finally look for non-thermal emission in the Suzaku HXD data. Results. The single-temperature model fails to reproduce the 0.5-10 keV continuum emission and Fe-K lines measured by XIS simultaneously. A two-temperature model with a very hot component improves the fit, although the XIS data can only provide a lower limit to the temperature of the hot component. In the Suzaku HXD data, we detect hard X-ray emission above the background in the 12-40 keV band at the 9 sigma level; however, the significance becomes marginal when the systematic error in the background estimation is included. With the joint analysis of the Suzaku and Chandra data, we determine the temperature of the hot gas in the SE region to be 25.3(-4.5)(+6.1) (statistical; 90% confidence level)(-9.5)(+6.9) ( systematic; 90% confidence level) keV, which is in an excellent agreement with the previous joint analysis of the SZ effect in radio and the Chandra X-ray data. This is the first time that the X-ray analysis alone provides a good measurement of the hot component temperature in the SE region, which is possible because of Suzaku's unprecedented sensitivity over the wide X-ray band. These results indicate strongly that RX J1347.5-1145 has undergone a recent, violent merger. The spectral analysis shows that the SE component is consistent with being thermal. We measure the 3 sigma upper limit to the non-thermal flux, F < 8 x 10(-12) erg s(-1) cm(-2) in the 12-60 keV band, which provides a limit on the inverse Compton scattering of relativistic electrons off the CMB photons. Combining this limit with the discovery of a radio mini halo in this cluster at 1.4 GHz, which measures the synchrotron radiation, we find a lower limit to the strength of the intracluster magnetic field, such that B > 0.007 mu G., 2008年11月, 491, 2, 363, 377, 10.1051/0004-6361:200810122

  DOI URL
• 査読無し, 英語, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, WILEY-BLACKWELL, A bright, dust-obscured, millimetre-selected galaxy beyond the Bullet Cluster (1E0657-56), G. W. Wilson; D. H. Hughes; I. Aretxaga; H. Ezawa; J. E. Austermann; S. Doyle; D. Ferrusca; I. Hernandez-Curiel; R. Kawabe; T. Kitayama; K. Kohno; A. Kuboi; H. Matsuo; P. D. Mauskopf; Y. Murakoshi; A. Montana; P. Natarajan; T. Oshima; N. Ota; T. A. Perera; J. Rand; K. S. Scott; K. Tanaka; M. Tsuboi; C. C. Williams; N. Yamaguchi; M. S. Yun, Deep 1.1 mm continuum observations of 1E0657-56 (the 'Bullet Cluster') taken with the millimeter-wavelength camera AzTEC on the 10-m Atacama Submillimeter Telescope Experiment (ASTE), have revealed an extremely bright (S(1.1 mm) = 15.9 mJy) unresolved source. This source, MMJ065837-5557.0, lies close to a maximum in the density of underlying mass distribution, towards the larger of the two interacting clusters as traced by the weak-lensing analysis of Clowe et al. Using optical-infrared (IR) colours, we argue that MMJ065837-5557.0 lies at a redshift of z = 2.7 +/- 2. A lensing-derived mass model for the Bullet Cluster shows a critical line (caustic) of magnification within a few arcsec of the AzTEC source, sufficient to amplify the intrinsic millimetre-wavelength flux of the AzTEC galaxy by a factor of > 20. After subtraction of the foreground cluster emission at 1.1 mm due to the Sunyaev-Zel'dovich effect, and correcting for the magnification, the rest-frame far-IR luminosity of MMJ065837-5557.0 is <= 10(12) L(circle dot), characteristic of a luminous infrared galaxy (LIRG). We explore various scenarios to explain the colours, morphologies and positional offsets between the potential optical and IR counterparts, and their relationship with MMJ065837-5557.0. Until higher resolution and more sensitive (sub)millimetre observations are available, the detection of background galaxies close to the caustics of massive lensing clusters offers the only opportunity to study this intrinsically faint millimetre-galaxy population., 2008年11月, 390, 3, 1061, 1070, 10.1111/j.1365-2966.2008.13774.x

  DOI URL
• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, Suzaku broad-band spectroscopy of RX J1347.5-1145: constraints on the extremely hot gas and non-thermal emission, N. Ota; K. Murase; T. Kitayama; E. Komatsu; M. Hattori; H. Matsuo; T. Oshima; Y. Suto; K. Yoshikawa, Context. We present the results of our analysis of long Suzaku observations (149 ks and 122 ks for XIS and HXD, respectively) of the most X-ray luminous galaxy cluster, RX J1347.5-1145, at z = 0.451. Aims. To understand the gas physics of a violent, cluster merger, we study physical properties of the hot (similar to 20 keV) gas clump in the south-east ( SE) region discovered previously by Sunyaev-Zel'dovich (SZ) effect observations. Using hard X-ray data, a signature of non-thermal emission is also explored. Methods. We perform single as well as multi-temperature fits to the Suzaku XIS spectra. The Suzaku XIS and HXD, and the Chandra ACIS-I data are then combined to examine the properties of the hot gas component in the SE region. We finally look for non-thermal emission in the Suzaku HXD data. Results. The single-temperature model fails to reproduce the 0.5-10 keV continuum emission and Fe-K lines measured by XIS simultaneously. A two-temperature model with a very hot component improves the fit, although the XIS data can only provide a lower limit to the temperature of the hot component. In the Suzaku HXD data, we detect hard X-ray emission above the background in the 12-40 keV band at the 9 sigma level; however, the significance becomes marginal when the systematic error in the background estimation is included. With the joint analysis of the Suzaku and Chandra data, we determine the temperature of the hot gas in the SE region to be 25.3(-4.5)(+6.1) (statistical; 90% confidence level)(-9.5)(+6.9) ( systematic; 90% confidence level) keV, which is in an excellent agreement with the previous joint analysis of the SZ effect in radio and the Chandra X-ray data. This is the first time that the X-ray analysis alone provides a good measurement of the hot component temperature in the SE region, which is possible because of Suzaku's unprecedented sensitivity over the wide X-ray band. These results indicate strongly that RX J1347.5-1145 has undergone a recent, violent merger. The spectral analysis shows that the SE component is consistent with being thermal. We measure the 3 sigma upper limit to the non-thermal flux, F < 8 x 10(-12) erg s(-1) cm(-2) in the 12-60 keV band, which provides a limit on the inverse Compton scattering of relativistic electrons off the CMB photons. Combining this limit with the discovery of a radio mini halo in this cluster at 1.4 GHz, which measures the synchrotron radiation, we find a lower limit to the strength of the intracluster magnetic field, such that B > 0.007 mu G., 2008年11月, 491, 2, 363, 377, 10.1051/0004-6361:200810122

  DOI URL
• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」衛星によるMS1512.4+3647銀河団の重元素の研究, 川原田円; 北口貴雄; 中澤知洋; 牧島一夫; 山崎典子; 太田直美; 深沢泰司; 松下恭子; 佐藤浩介; 大橋隆哉, 2008年08月20日, 2008, 214

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku observation of HCG 62: Temperature, abundance, and extended hard X-ray emission profiles, Kazuyo Tokoi; Kosuke Sato; Yoshitaka Ishisaki; Takaya Ohashi; Noriko Y. Yamasaki; Kazuhiro Nakazawa; Kyoko Matsushita; Yasushi Fukazawa; Akio Hoshino; Takayuki Tamura; Chihiro Egawa; Naomi Kawano; Naomi Ota; Naoki Isobe; Madoka Kawaharada; Hisamitsu Awaki; John P. Hughes, The compact group of galaxies HCG 62 (z = 0.0145) was observed for 120 ks with Suzaku XIS and HXD-PIN. The XIS spectra for four annular regions were fitted with a two-temperature vapec model with variable abundance, combined with the foreground Galactic component. The Galactic component was described by a two-temperature apec model, and constrained to have a common surface brightness among the four annuli. We confirmed the multitemperature nature of the intra-group medium, as reported previously, with a doughnut-like high temperature ring at radii 3'3-6'5. Abundances of Mg, Si, S, and Fe were well-constrained. We examined the possible "high-abundance arc" at'- 2; southwest from the center; however, Suzaku data did not confirm it. We suspect that it is a misidentification of an excess hot component in this region as the Fe line. Neither XIS (5-12 keV) nor HXD-PIN (12-40 keV) gave positive detection of the extended hard X-rays previously reported with ASCA, although our upper limit did not exclude the ASCA result. The 5-12 keV intensity in the r < 33 region turned out to be 70 19% higher than the nominal CXB level, and Chandra and Suzaku data suggest a concentration of hard X-ray sources with an average photon index of F = 1.3 8 0.06. The cumulative mass of 0, Fe, and Mg in the intra-group medium and the metal mass-to-light ratio were compared with those in other groups. The possible role of AGN or galaxy mergers in this group is also discussed., 2008年02月, 60, S317, S331, 10.1093/pasj/60.sp1.S317

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• 査読無し, 英語, CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS, SCIENCE PRESS, L-x-T Relation and Thermal Evolution of Galaxy Clusters, Naomi Ota; Tetsu Kitayama; Kuniaki Masai; Kazuhisa Mitsuda, We present an observational approach to constrain the global structure and evolution of the intracluster medium utilizing the ROSAT and ASCA distant cluster sample. From statistical analysis of the gas density profile and the connection to the L-X-T relation under the beta-model, the scaled gas profile is found to be nearly universal for the outer region. On the other hand, a large density scatter exists in the core region and there is clearly a deviation from the self-similar scaling for clusters with a small core. The discovery of the existence of an X-ray fundamental plane in the distant cluster sample suggests that the cooling time (t(cool)) is a parameter to control the gas structure. The appearance of small cores in regular clusters may be strongly connected with the thermal evolution. We derive the luminosity-ambient temperature (T') relation, assuming the universal temperature profile for the clusters with short and find the dispersion around the relation significantly decreases and the slope becomes marginally less steep. Considering a correlation between and the X-ray morphology, the observational results lead us to draw a phenomenological picture: after a cluster collapses and t(cool) falls below the age of the universe, the core cools radiatively with quasi-hydrostatic balancing in the gravitational potential, and the central density gradually becomes higher to evolve from an outer-core-dominant cluster, which follows the self-similarity, to inner-core-dominant cluster., 2008年, 8, 84, 92
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku observation of HCG 62: Temperature, abundance, and extended hard X-ray emission profiles, Kazuyo Tokoi; Kosuke Sato; Yoshitaka Ishisaki; Takaya Ohashi; Noriko Y. Yamasaki; Kazuhiro Nakazawa; Kyoko Matsushita; Yasushi Fukazawa; Akio Hoshino; Takayuki Tamura; Chihiro Egawa; Naomi Kawano; Naomi Ota; Naoki Isobe; Madoka Kawaharada; Hisamitsu Awaki; John P. Hughes, The compact group of galaxies HCG 62 (z = 0.0145) was observed for 120 ks with Suzaku XIS and HXD-PIN. The XIS spectra for four annular regions were fitted with a two-temperature vapec model with variable abundance, combined with the foreground Galactic component. The Galactic component was described by a two-temperature apec model, and constrained to have a common surface brightness among the four annuli. We confirmed the multitemperature nature of the intra-group medium, as reported previously, with a doughnut-like high temperature ring at radii 3'3-6'5. Abundances of Mg, Si, S, and Fe were well-constrained. We examined the possible "high-abundance arc" at'- 2; southwest from the center; however, Suzaku data did not confirm it. We suspect that it is a misidentification of an excess hot component in this region as the Fe line. Neither XIS (5-12 keV) nor HXD-PIN (12-40 keV) gave positive detection of the extended hard X-rays previously reported with ASCA, although our upper limit did not exclude the ASCA result. The 5-12 keV intensity in the r < 33 region turned out to be 70 19% higher than the nominal CXB level, and Chandra and Suzaku data suggest a concentration of hard X-ray sources with an average photon index of F = 1.3 8 0.06. The cumulative mass of 0, Fe, and Mg in the intra-group medium and the metal mass-to-light ratio were compared with those in other groups. The possible role of AGN or galaxy mergers in this group is also discussed., 2008年02月, 60, S317, S331, 10.1093/pasj/60.sp1.S317

  DOI URL
• 査読無し, 英語, CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS, SCIENCE PRESS, L-x-T Relation and Thermal Evolution of Galaxy Clusters, Naomi Ota; Tetsu Kitayama; Kuniaki Masai; Kazuhisa Mitsuda, We present an observational approach to constrain the global structure and evolution of the intracluster medium utilizing the ROSAT and ASCA distant cluster sample. From statistical analysis of the gas density profile and the connection to the L-X-T relation under the beta-model, the scaled gas profile is found to be nearly universal for the outer region. On the other hand, a large density scatter exists in the core region and there is clearly a deviation from the self-similar scaling for clusters with a small core. The discovery of the existence of an X-ray fundamental plane in the distant cluster sample suggests that the cooling time (t(cool)) is a parameter to control the gas structure. The appearance of small cores in regular clusters may be strongly connected with the thermal evolution. We derive the luminosity-ambient temperature (T') relation, assuming the universal temperature profile for the clusters with short and find the dispersion around the relation significantly decreases and the slope becomes marginally less steep. Considering a correlation between and the X-ray morphology, the observational results lead us to draw a phenomenological picture: after a cluster collapses and t(cool) falls below the age of the universe, the core cools radiatively with quasi-hydrostatic balancing in the gravitational potential, and the central density gradually becomes higher to evolve from an outer-core-dominant cluster, which follows the self-similarity, to inner-core-dominant cluster., 2008年, 8, 84, 92
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, X-ray study of temperature and abundance profiles of the cluster of galaxies Abell 1060 with Suzaku, Kosuke Sato; Noriko Y. Yamasaki; Manabu Ishida; Yoshitaka Ishisaki; Takaya Ohashi; Hajime Kawahara; Takao Kitaguchi; Madoka Kawaharada; Motohide Kokubun; Kazuo Makishima; Naomi Ota; Kazuhiro Nakazawa; Takayuki Tamura; Kyoko Matsushita; Naomi Kawano; Yasushi Fukazawa; John P. Hughes, We carried out observations of the central and 20' east offset regions of the cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral analysis has revealed temperature and abundance profiles of Abell 1060 out to 27' similar or equal to 380 h(70)(-1) kpc, which corresponds to similar to 0.25 r(180). Temperature decrease of the intra-cluster medium 70 from 3.4 keV at the center to 2.2 keV in the outskirt region was clearly observed. The abundances of Si, S, and Fe also decrease by more than 50% from the center to the outer region, while Mg shows a fairly constant abundance distribution at similar to 0.7 solar within r less than or similar to 17'. O shows a lower abundance of similar to 0.3 solar in the central region (r less than or similar to 6'), and indicates a similar feature with Mg; however, it is sensitive to the estimated contribution of the Galactic components of kT(1) similar to 0.15 keV and kT(2) similar to 0.7 keV in the outer annuli (r greater than or similar to 13'). Systematic effects due to the point-spread function tails, contamination on the XIS filters, instrumental background, cosmic and/or Galactic X-ray background, and the assumed solar abundance tables were carefully examined. The results on the temperature and abundances of Si, S, and Fe are consistent with those derived by XMM-Newton at r less than or similar to 13'. The formation and metal-enrichment process of the cluster are discussed based on the present results., 2007年04月, 59, 2, 299, 317, 10.1093/pasj/59.2.299

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, X-ray study of temperature and abundance profiles of the cluster of galaxies Abell 1060 with Suzaku, Kosuke Sato; Noriko Y. Yamasaki; Manabu Ishida; Yoshitaka Ishisaki; Takaya Ohashi; Hajime Kawahara; Takao Kitaguchi; Madoka Kawaharada; Motohide Kokubun; Kazuo Makishima; Naomi Ota; Kazuhiro Nakazawa; Takayuki Tamura; Kyoko Matsushita; Naomi Kawano; Yasushi Fukazawa; John P. Hughes, We carried out observations of the central and 20' east offset regions of the cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral analysis has revealed temperature and abundance profiles of Abell 1060 out to 27' similar or equal to 380 h(70)(-1) kpc, which corresponds to similar to 0.25 r(180). Temperature decrease of the intra-cluster medium 70 from 3.4 keV at the center to 2.2 keV in the outskirt region was clearly observed. The abundances of Si, S, and Fe also decrease by more than 50% from the center to the outer region, while Mg shows a fairly constant abundance distribution at similar to 0.7 solar within r less than or similar to 17'. O shows a lower abundance of similar to 0.3 solar in the central region (r less than or similar to 6'), and indicates a similar feature with Mg; however, it is sensitive to the estimated contribution of the Galactic components of kT(1) similar to 0.15 keV and kT(2) similar to 0.7 keV in the outer annuli (r greater than or similar to 13'). Systematic effects due to the point-spread function tails, contamination on the XIS filters, instrumental background, cosmic and/or Galactic X-ray background, and the assumed solar abundance tables were carefully examined. The results on the temperature and abundances of Si, S, and Fe are consistent with those derived by XMM-Newton at r less than or similar to 13'. The formation and metal-enrichment process of the cluster are discussed based on the present results., 2007年04月, 59, 2, 299, 317, 10.1093/pasj/59.2.299

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• 査読無し, 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 26pSF-14 「すざく」で観測された銀河群HCG 62の温度と重元素分布の研究(26pSF X線・γ線,宇宙線・宇宙物理領域), 床井 和世; 佐藤 浩介; 星野 晶夫; 石崎 欣尚; 大橋 隆哉; 中澤 知洋; 田村 隆幸; 山崎 典子; 石田 学; 川原田 円; 国分 紀秀; 北口 貴雄; 江川 千尋; 戸塚 都; 深沢 泰司; 太田 直美; 磯部 直樹; 松下 恭子; 栗木 久光; Hornschemeier Ann; Huhes John P, 2007年02月28日, 62, 1, 102, 102
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku observations of the Centaurus cluster: Absence of bulk motions in the intracluster medium, Naomi Ota; Yasushi Fukazawa; Andrew C. Fabian; Takehiro Kanemaru; Madoka Kawaharada; Naomi Kawano; Richard L. Kelley; Takao Kitaguchi; Kazuo Makishima; Kyoko Matsushita; Kouichi Murase; Kazuhiro Nakazawa; Takaya Ohashi; Jeremy S. Sanders; Takayuki Tamura; Yuji Urata, The Centaurus cluster (z = 0.0104) was observed with the X-ray Imaging Spectrometer (XIS) onboard the Suzaku X-ray satellite in three pointings, one centered on the cluster core and the other two offset by +/- 8' in declination. To search for possible bulk motions of the intracluster medium, the central energy of a He-like Fe K line (at a rest-frame energy of 6.7 keV) was examined to look for a positional dependence. Over spatial scales of 50 kpc to 140 kpc around the cluster core, the central line energy was found to be constant within a calibration error of 15 eV. The 90% upper limit on the line-of-sight velocity difference is vertical bar Delta upsilon vertical bar < 1400km s(-1) giving a tighter constraint than previous measurements. The significant velocity gradients inferred from a previous Chandra study were not detected between two pairs of rectangular regions near the cluster core. These results suggest that the bulk velocity does not largely exceed the thermal velocity of the gas in the central region of the Centaurus cluster. The mean redshift of the intracluster medium was determined to be 0.0097, in agreement with the optical redshift of the cluster within the calibration uncertainty. Implications of the present results for estimating the cluster mass are briefly discussed., 2007年01月, 59, S351, S359, 10.1093/pasj/59.sp1.S351

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku observation of the metallicity distribution in the intracluster medium of the Fornax cluster, Kyoko Matsushita; Yasushi Fukazawa; John P. Hughes; Takao Kitaguchi; Kazuo Makishima; Kazuhiro Nakazawa; Takaya Ohashi; Naomi Ota; Takayuki Tamura; Miyako Tozuka; Takeshi Go Tsuru; Yuji Urata; Noriko Y. Yamasaki, The metallicity distribution in the Fornax cluster was studied with the XIS instrument on board the Suzaku satellite. The K-shell lines of O and Mg were resolved clearly, and the abundances of O, Mg, Si, S, and Fe were measured with great accuracy. The region within a 4' radius of NGC 1399 shows approximately solar abundances of Fe, Si, and S, while the O/Fe and Mg/Fe abundance ratios are about 0.4-0.5 and 0.7 in solar units, respectively. In the outer region of the radius range 6' < r < 23', the Fe and Si abundances drop to 0.4-0.5 solar and show no significant gradient within this region. The abundance ratios, O/Fe and Mg/Fe, are consistent with those in the central region. We also measured the Fe abundance around NGC 1404 to be approximately solar, and the 0, Ne, and Mg abundances to be 0.5-0.7 times the Fe level. A significant relative enhancement of Fe within 130kpc of NGC 1399 and in NGC 1404 indicates an origin in SN Ia, in contrast to the species 0, Ne, and Mg, which reflect the stellar metallicity. The mass-to-light ratios for O and Fe within 130kpc of NGC 1399 are over an order of magnitude lower than those in rich clusters, reflecting the metal enrichment history of this poor cluster., 2007年01月, 59, SP1, S327, S338, 10.1093/pasj/59.sp1.S327

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, The Suzaku high resolution X-ray Spectrometer, Richard L. Kelley; Kazuhisa Mitsuda; Christine A. Allen; Petar Arsenovic; Michael D. Audley; Thomas G. Bialas; Kevin R. Boyce; Robert F. Boyle; Susan R. Breon; Gregory V. Brown; Jean Cottam; Michael J. DiPirro; Ryuichi Fujmoto; Tae Furusho; Keith C. Gendreau; Gene G. Gochar; Oscar Gonzalez; Masayuki Hirabayashi; Stephen S. Holt; Hajime Inoue; Manabu Ishida; Yoshitaka Ishisaki; Carol S. Jones; Ritva Keski-Kuha; Caroline A. Kilbourne; Dan McCammon; Umeyo Morita; S. Harvey Moseley; Brent Mott; Katsuhiro Narasaki; Yoshiaki Ogawara; Takaya Ohashl; Naomi Ota; John S. Panek; F. Scott Porter; Aristides Serlemitsos; Peter J. Shirron; Gary A. Sneiderman; Andrew E. Szymkowiak; Yoh Takei; June L. Tveekrem; Stephen M. Volz; Mikio Yamamoto; Noriko Y. Yamasaki, The X-Ray Spectrometer (XRS) has been designed to provide the Suzaku Observatory with non-dispersive, high-resolution X-ray spectroscopy. As designed, the instrument covers the energy range 0.3 to 12 keV, which encompasses the most diagnostically rich part of the X-ray band. The sensor consists of a 32-channel array of X-ray microcalorimeters, each with an energy resolution of about 6 eV. The very low temperature required for operation of the array (60 mK) is provided by a four-stage cooling system containing a single-stage adiabatic demagnetization refrigerator, a superfluid-helium cryostat, a solid-neon dewar, and a single-stage, Stirling-cycle cooler. The Suzaku/XRS is the first orbiting X-ray microcalorimeter spectrometer and was designed to last more than three years in orbit. The early verification phase of the mission demonstrated that the instrument worked properly and that the cryogen consumption rate was low enough to ensure a mission lifetime exceeding 3 years. However, the liquid-He cryogen was completely vaporized two weeks after opening the dewar guard vacuum vent. The problem has been traced to inadequate venting of the dewar He and Ne gases out of the spacecraft and into space. In this paper we present the design and ground testing of the XRS instrument, and then describe the in-flight performance. An energy resolution of 6 eV was achieved during pre-launch tests and a resolution of 7 eV was obtained in orbit. The slight degradation is due to the effects of cosmic rays., 2007年01月, 59, SP1, S77, S112, 10.1093/pasj/59.sp1.S77

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Hard X-ray Detector (HXD) on board Suzaku, Tadayuki Takahashi; Keiichi Abe; Manabu Endo; Yasuhiko Endo; Yuuichiro Ezoe; Yasushi Fukazawa; Masahito Hamaya; Shinya Hirakuri; Soojing Hong; Michihiro Horii; Hokuto Inoue; Naoki Isobe; Takeshi Itoh; Naoko Iyomoto; Tuneyoshi Kamae; Daisuke Kasama; Jun Kataoka; Hiroshi Kato; Madoka Kawaharada; Naomi Kawano; Kengo Kawashima; Satoshi Kawasoe; Tetsuichi Kishishita; Takao Kitaguch; Yoshihito Kobayashi; Motohide Kokubun; Jun'ichi Kotoku; Manabu Kouda; Aya Kubota; Yoshikatsu Kuroda; Greg Madejski; Kazuo Makishima; Kazunori Masukama; Yukari Matsumoto; Takefumi Mitani; Ryohei Miyawaki; Tsunefumi Mizuno; Kunishiro Mori; Masanori Mori; Mio Murashima; Toshio Murakami; Kazuhiro Nakazawa; Hisako Niko; Masaharu Nomachi; Yuu Okada; Masanori Ohno; Kousuke Oonuki; Naomi Ota; Hideki Ozawa; Goro Sato; Shingo Shinoda; Masahiko Sugiho; Masaya Suzuki; Koji Taguchi; Hiromitsu Takahashi; Isao Takahashi; Shin'ichiro Takeda; Ken-ichi Tamura; Takayuki Tamura; Takaaki Tanaka; Chiharu Tanihata; Makoto Tashiro; Yukikatsu Terada; Shin'ya Tominaga; Yasunobu Uchiyama; Shin Watanabe; Kazutaka Yamaoka; Takayuki Yanagida; Daisuke Yonetoku, The Hard X-ray Detector (HXD) on board Suzaku covers a wide energy range from 10 keV to 600 keV by the combination of silicon PIN diodes and GSO scintillators. The HXD is designed to achieve an extremely low in-orbit background based on a combination of new techniques, including the concept of a well-type active shield counter. With an effective area of 142 cm(2) at 20 keV and 273 cm(2) at 150 keV, the background level at sea level reached similar to 1 X 10(-5) cts s(-1) cm(-2) keV(-1) at 30 keV for the PIN diodes, and similar to 2 X 10(-5) cts s(-1) cm(-2) keV(-1) at 100 keV, and similar to 7 X 10(-6) cts s(-1) cm(-2) keV(-1) at 200 keV for the phoswich counter. Tight active shielding of the HXD results in a large array of guard counters surrounding the main detector parts. These anti-coincidence counters, made of similar to 4 cm thick BGO crystals, have a large effective area for sub-MeV to MeV gamma-rays. They work as an excellent gamma-ray burst monitor with limited angular resolution (similar to 5 degrees). The on-board signal-processing system and the data transmitted to the ground are also described., 2007年01月, 59, SP1, S35, S51, 10.1093/pasj/59.sp1.S35

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, The X-ray observatory Suzaku, Kazuhisa Mitsuda; Mark Bautz; Hajime Inoue; Richard L. Kelley; Katsuji Koyama; Hideyo Kunieda; Kazuo Makshima; Yoshiaki Ogawara; Robert Petre; Tadayuki Takahashi; Hiroshi Tsunemi; Nicholas E. White; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Hisamitsu Awaki; Aya Bamba; Kevin Boyce; Gregory V. Brown; Kai-Wing Chan; Jean Cottam; Tadayasu Dotanli; John Doty; Ken Ebisawa; Yuichiro Ezoe; Andrew C. Fabian; Enectali Figueroa; Ryuichi Fujimoto; Yasushi Fukazawa; Tae Furusho; Akihiro Furuzawa; Keith Gendreau; Richard E. Griffiths; Yoshito Haba; Kenji Hamaguchi; Ilana Harrus; Gunther Hasinger; Isamu Hatsukade; Kiyoshi Hayashida; Patrick J. Henry; Junko S. Hiraga; Stephen S. Holt; Ann Hornschemeier; John P. Hughes; Una Hwang; Manabu Ishida; Yoshitaka Ishisaki; Naoki Isobe; Masayuki Itoh; Naoko Iyomoto; Steven M. Kahn; Tuneyoshi Kamae; Hideaki Katagiri; Jun Kataoka; Haruyoshi Katayama; Nobuyuki Kawai; Caroline Kilbourne; Kenzo Kinugasa; Steve Kissel; Shunji Kitamoto; Mitsuhiro Kohama; Takayoshi Kohmura; Motohide Kokubun; Taro Kotani; Jun'ichi Kotoku; Aya Kubota; Greg M. Madejski; Yoshitomo Maeda; Fumiyoshi Makino; Alex Markowitz; Chiho Matsumoto; Hironori Matsumoto; Masaru Matsuoka; Kyoko Matsushita; Dan McCammon; Tatehiko Mihara; Kazutami Misaki; Emi Miyata; Tsunefumi Mizuno; Koji Mori; Hideyuki Mori; Mikio Morii; Harvey Moseley; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky; Fumiaki Nagase; Masaaki Namiki; Hitoshi Negoro; Kazubiro Nakazawa; John A. Nousek; Takashi Okajima; Yasushi Ogasaka; Takaya Ohashi; Tai Oshima; Naomi Ota; Masanobu Ozaki; Hideki Ozawa; Arvind N. Parmar; William D. Pence; F. Scott Porter; James N. Reeves; George R. Ricker; Ikuya Sakurai; Wilton T. Sanders; Atsushi Senda; Peter Serlemitsos; Ryo Shibata; Yang Soong; Randall Smith; Motoko Suzuki; Andrew E. Szymkowiak; Hiromitsu Takahashi; Torn Tamagawa; Keisuke Tamura; Takayuki Tamura; Yasuo Tanaka; Makoto Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Hiroshi Tomida; Ken'ichi Torii; Yohko Tsuboi; Masahiro Tsujimoto; Takeshi Go Tsuru; Martin J. L. Turner; Yoshihiro Ueda; Shiro Ueno; Masaru Ueno; Shin'ichiro Uno; Yuji Urata; Shin Watanabe; Norimasa Yamamoto; Kazutaka Yamaoka; Noriko Y. Yamasaki; Koujun Yamashita; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Daisuke Yonetoku; Atsumasa Yoshida, High-sensitivity wide-band X-ray spectroscopy is the key feature of the Suzaku X-ray observatory, launched on 2005 July 10. This paper summarizes the spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, the high-throughput X-ray telescopes, X-ray CCD cameras, non-imaging hard X-ray detector are also described., 2007年01月, 59, SP1, S1, S7, 10.1093/pasj/59.sp1.S1

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• 査読無し, その他, XMM-Newton: The Next Decade, Suzaku Study of hard X-ray Emission from Nearby Galaxy Clusters, 太田 直美; Kitaguchi, T; Nakazawa, N; Makishima, K; Kawaharada, M; Ota, N; Kokubun, M; Yamasaki, N; Kawano, N; Fukazawa, Y; Sato, K; Ohashi, T; Murase, K; Urata, Y; Tashiro, M; Furusawa, A; Suzaku Team, 2007年
• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, The 7-steps of the data analysis, Yukikatsu Terada; Aya Bamba; Junko S. Hiraga; Naoki Isobe; Aya Kubota; Naomi Ota; Piero Ranalli; Atsushi Senda; Motoko Suzuki; Toru Tamagawa; Yuji Urata; Masanobu Ozaki; Ken Ebisawa; Yoshitaka Ishisaki; Hironori Matsumoto; Izumi Yamagishi; Takayuki Tamura; Koji Mukai; Lorella Angellini; Kenji Hamaguchi, It may seem to be difficult to analyze the Suzaku data, but the data structure and the tools are rather simple. We have constructed the way to process Suzaku FITS data and ftools for over ten years. We have prepared three kinds of manuals to analyze the data; Seven step manual of the XIS and the HXD for beginners, first step manual to walk through the analyses, and the ABC guide as a full manual. In the actual analyses, we have to be careful about events in operation and the limitations in the calibration of instruments. In this paper, the data structure, tools, and manuals with activities of help desks, current status of processing are summarized., 2007年, 169, 169, 312, 315
• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Suzaku survey for non-thermal hard X-ray emission from clusters of galaxies, Kazuhiro Nakazawa; Naomi Kawano; Yasushi Fukazawa; Chihiro Egawa; Takao Kitaguchi; Madoka Kawaharada; Kazuo Makishima; Naomi Ota; Kazuyo Tokoi; Kosuke Sato; Yoshitaka Ishisaki; Takaya Ohashi; Noriko Yamasaki, Status of the Suzaku survey for non-thermal hard X-ray emission from clusters of galaxies is reported. Utilizing the lowest and stable detector background of both the HXD and the XIS instruments, Suzaku achieved high sensitivity for hard X-ray diffuse emission survey. Deep (>= 100 ks) observations of a merging cluster A3376 present an upper limit of similar to 10(-11) erg cm(-2) s(-1) in the 15-50 keV band (Kawano et al. and this work). Other analyses using the HXD (Centaurus and A1060, Kitaguchi et al.) and the XIS (HCG 62, Tokoi et al.) are also briefly summarized., 2007年, 169, 169, 45, 48, 10.1143/PTPS.169.45

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• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Suzaku observation of Abell 2204: Galaxy cluster gas temperature measurement up to the virial radius, Thomas H. Reiprich; Daniel S. Hudson; Oxana-Elena Nenestyan; Kosuke Sato; Yoshitaka Ishisaki; Akio Hoshino; Takaya Ohashi; Naomi Ota; Yutaka Fujita; Guenther Hasinger, Measurements of the intracluster gas temperatures out to large radii, where much of the cluster mass resides, are of the utmost importance for the use of clusters in precision cosmology and for Studies of cluster physics. Previous attempts to measure temperatures at the cluster virial radius have failed. The preliminary results from the Suzaku observation of Abell 2204 reported here show that such measurements appear feasible now for the first time, if care is taken to account for background and PSF effects., 2007年, 169, 169, 33, 36
• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Absence of bulk motions of the intracluster medium in the Centaurus cluster, Naomi Ota; Yasushi Fukazawa; Andrew C. Fabian; Takehiro Kanemaru; Madoka Kawaharada; Naomi Kawano; Richard L. Kelley; Takao Kitacuchi; Kazuo Makishima; Kyoko Matsusihita; Kouichi Murase; Kazuhiro Nakazawa; Takaya Ohashi; Jeremy S. Sanders; Takayuki Tamura; Yuji Urata, We present results from the Suzaku observations of a nearby cluster, the Centaurus cluster (z = 0.0104). Three pointing observations of the cluster were carried out with the Suzaku XIS in December 2005, and the Doppler shift of the iron K lines was investigated in detail to constrain the bulk velocity of the intracluster medium (ICM) in its core region. From the spectral analysis, no significant velocity difference was detected within calibration uncertainty of +/- 700 kms(-1) over a spatial scale of 50 kpc in the central 240 kpc region. The 90% upper limit on the line-of-sight velocity is < 1400 km s(-1), giving a tighter constraint than the previous measurements. The significant velocity gradients inferred from the previous Chandra observations were not detected in two pairs of regions near the cluster core. These results suggest that the bulk velocity does not largely exceed the thermal velocity of the gas in the central region of the Centaurus cluster. Implications of the present results for the estimation of the cluster mass are discussed., 2007年, 169, 169, 25, 28
• 査読無し, 英語, ESO Astrophysics Symposia, A Suzaku observation of the cluster of galaxies A1060, K. Sato; N. Y. Yamasaki; M. Ishida; Y. Ishisaki; T. Ohashi; T. Kitaguchi; M. Kawaharada; M. Kokubun; K. Makishima; N. Ota; K. Nakazawa; T. Tamura; K. Matsushita; N. Kawano; Y. Fukazawa; J. P. Hughes, We carried out observations of the central and 20′ east offset regions of the cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral=analysis has revealed temperature and abundance profiles of Abell 1060 out to 27′ ≃ 380 h70 -1kpc, which corresponded to ∼0.3 rvir. The temperature decrease of the intra cluster medium from 3.4 keV at the center to 2.2 keV in the outskirt region are clearly observed. Si, S and Fe abundances also decrease by more than 50% from the center to the outer parts, while Mg shows a fairly constant abundance of ∼ 0.7 solar within r < 17′. O shows a lower abundance of ∼0.3 solar in the central region (r < 6′), and indicates a similar feature with Mg, however it is sensitive to the estimated contribution of the Galactic components at the outer annuli (r > 13′). Results on temperature and abundances of Si, S, and Fe are consistent with those derived by XMM-Newton at r < 13′ The formation and metal enrichment of the cluster are discussed based on implications of our results. © 2007 Springer-Verlag Berlin Heidelberg., 2007年, 2007, 398, 400, 10.1007/978-3-540-73484-0_73

  DOI URL
• 査読無し, 英語, ESO Astrophysics Symposia, New results with the XIS onboard suzaku, N. Ota; K. Matsushita, We present new results from the Suzaku XIS observations of two nearby clusters of galaxies, the Centaurus cluster and the Fornax cluster. For the Centaurus cluster, we investigated the Doppler shift of the iron K lines to constrain the bulk velocity of the intracluster medium (ICM) in its core region. We found that there is no significant velocity gradient within the calibration uncertainty: the 90% upper limit on the line-of-sight velocity difference is δ v < 1400 km s-1, providing a tighter constraint than the previous observations. Regarding the Fornax cluster, we studied metal abundances of the ICM out to a large radius. K-lines of O and Mg were clearly resolved and the abundance profiles of O, Mg, Si, S and Fe were derived to high accuracy. The central r < 4′ region shows the Fe, Si, and S abundances to be ∼1 solar, while the Fe and Si abundances drop to about 0.5 solar in the outer region. O/Fe and Mg/Fe are about 0.4-0.5 and 0.7 in unit of the solar ratio, respectively, and do not show any significant radial gradient. Implications of the results on each cluster are briefly discussed. © 2007 Springer-Verlag Berlin Heidelberg., 2007年, 2007, 389, 394, 10.1007/978-3-540-73484-0_71

  DOI URL
• 査読無し, 英語, HEATING VERSUS COOLING IN GALAXIES AND CLUSTERS OF GALAXIES, SPRINGER-VERLAG BERLIN, Chandra and XMM-Newton observations of the group of galaxies HCG 62, T. Ohashi; U. Morita; Y. Ishisaki; N. Y. Yamasaki; N. Ota; N. Kawano; Y. Fukazawa, We present results from Chandra and XMM-Newton observations of the bright group of galaxies HCG 62. The two cavities in the central region show no significant change of temperature compared with that in the surrounding region. We studied radial distributions of temperature and metal abundance. Two temperatures are required in the inner r < 2' (35 kpc) region, and a sharp drop of temperature is seen at r similar to 5' where the gas may not be in hydrostatic equilibrium. The metal distribution suggests that iron and silicon are produced by type Ia supernova in the central galaxy, while galactic winds by type II supernova have caused a wider distribution of oxygen. The pressure due to electrons and magnetic fields is too low to displace the group hot gas, and other pressure contributions from high energy protons or by galaxy-scale dynamical motions are nearly 700 times higher. Detailed accounts are given in [5]., 2007年, 112, +, 10.1007/978-3-540-73484-0_21

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku observations of the Centaurus cluster: Absence of bulk motions in the intracluster medium, Naomi Ota; Yasushi Fukazawa; Andrew C. Fabian; Takehiro Kanemaru; Madoka Kawaharada; Naomi Kawano; Richard L. Kelley; Takao Kitaguchi; Kazuo Makishima; Kyoko Matsushita; Kouichi Murase; Kazuhiro Nakazawa; Takaya Ohashi; Jeremy S. Sanders; Takayuki Tamura; Yuji Urata, The Centaurus cluster (z = 0.0104) was observed with the X-ray Imaging Spectrometer (XIS) onboard the Suzaku X-ray satellite in three pointings, one centered on the cluster core and the other two offset by +/- 8' in declination. To search for possible bulk motions of the intracluster medium, the central energy of a He-like Fe K line (at a rest-frame energy of 6.7 keV) was examined to look for a positional dependence. Over spatial scales of 50 kpc to 140 kpc around the cluster core, the central line energy was found to be constant within a calibration error of 15 eV. The 90% upper limit on the line-of-sight velocity difference is vertical bar Delta upsilon vertical bar < 1400km s(-1) giving a tighter constraint than previous measurements. The significant velocity gradients inferred from a previous Chandra study were not detected between two pairs of rectangular regions near the cluster core. These results suggest that the bulk velocity does not largely exceed the thermal velocity of the gas in the central region of the Centaurus cluster. The mean redshift of the intracluster medium was determined to be 0.0097, in agreement with the optical redshift of the cluster within the calibration uncertainty. Implications of the present results for estimating the cluster mass are briefly discussed., 2007年01月, 59, S351, S359, 10.1093/pasj/59.sp1.S351

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Suzaku observation of the metallicity distribution in the intracluster medium of the Fornax cluster, Kyoko Matsushita; Yasushi Fukazawa; John P. Hughes; Takao Kitaguchi; Kazuo Makishima; Kazuhiro Nakazawa; Takaya Ohashi; Naomi Ota; Takayuki Tamura; Miyako Tozuka; Takeshi Go Tsuru; Yuji Urata; Noriko Y. Yamasaki, The metallicity distribution in the Fornax cluster was studied with the XIS instrument on board the Suzaku satellite. The K-shell lines of O and Mg were resolved clearly, and the abundances of O, Mg, Si, S, and Fe were measured with great accuracy. The region within a 4' radius of NGC 1399 shows approximately solar abundances of Fe, Si, and S, while the O/Fe and Mg/Fe abundance ratios are about 0.4-0.5 and 0.7 in solar units, respectively. In the outer region of the radius range 6' < r < 23', the Fe and Si abundances drop to 0.4-0.5 solar and show no significant gradient within this region. The abundance ratios, O/Fe and Mg/Fe, are consistent with those in the central region. We also measured the Fe abundance around NGC 1404 to be approximately solar, and the 0, Ne, and Mg abundances to be 0.5-0.7 times the Fe level. A significant relative enhancement of Fe within 130kpc of NGC 1399 and in NGC 1404 indicates an origin in SN Ia, in contrast to the species 0, Ne, and Mg, which reflect the stellar metallicity. The mass-to-light ratios for O and Fe within 130kpc of NGC 1399 are over an order of magnitude lower than those in rich clusters, reflecting the metal enrichment history of this poor cluster., 2007年01月, 59, SP1, S327, S338, 10.1093/pasj/59.sp1.S327

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, The Suzaku high resolution X-ray Spectrometer, Richard L. Kelley; Kazuhisa Mitsuda; Christine A. Allen; Petar Arsenovic; Michael D. Audley; Thomas G. Bialas; Kevin R. Boyce; Robert F. Boyle; Susan R. Breon; Gregory V. Brown; Jean Cottam; Michael J. DiPirro; Ryuichi Fujmoto; Tae Furusho; Keith C. Gendreau; Gene G. Gochar; Oscar Gonzalez; Masayuki Hirabayashi; Stephen S. Holt; Hajime Inoue; Manabu Ishida; Yoshitaka Ishisaki; Carol S. Jones; Ritva Keski-Kuha; Caroline A. Kilbourne; Dan McCammon; Umeyo Morita; S. Harvey Moseley; Brent Mott; Katsuhiro Narasaki; Yoshiaki Ogawara; Takaya Ohashl; Naomi Ota; John S. Panek; F. Scott Porter; Aristides Serlemitsos; Peter J. Shirron; Gary A. Sneiderman; Andrew E. Szymkowiak; Yoh Takei; June L. Tveekrem; Stephen M. Volz; Mikio Yamamoto; Noriko Y. Yamasaki, The X-Ray Spectrometer (XRS) has been designed to provide the Suzaku Observatory with non-dispersive, high-resolution X-ray spectroscopy. As designed, the instrument covers the energy range 0.3 to 12 keV, which encompasses the most diagnostically rich part of the X-ray band. The sensor consists of a 32-channel array of X-ray microcalorimeters, each with an energy resolution of about 6 eV. The very low temperature required for operation of the array (60 mK) is provided by a four-stage cooling system containing a single-stage adiabatic demagnetization refrigerator, a superfluid-helium cryostat, a solid-neon dewar, and a single-stage, Stirling-cycle cooler. The Suzaku/XRS is the first orbiting X-ray microcalorimeter spectrometer and was designed to last more than three years in orbit. The early verification phase of the mission demonstrated that the instrument worked properly and that the cryogen consumption rate was low enough to ensure a mission lifetime exceeding 3 years. However, the liquid-He cryogen was completely vaporized two weeks after opening the dewar guard vacuum vent. The problem has been traced to inadequate venting of the dewar He and Ne gases out of the spacecraft and into space. In this paper we present the design and ground testing of the XRS instrument, and then describe the in-flight performance. An energy resolution of 6 eV was achieved during pre-launch tests and a resolution of 7 eV was obtained in orbit. The slight degradation is due to the effects of cosmic rays., 2007年01月, 59, SP1, S77, S112, 10.1093/pasj/59.sp1.S77

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Hard X-ray Detector (HXD) on board Suzaku, Tadayuki Takahashi; Keiichi Abe; Manabu Endo; Yasuhiko Endo; Yuuichiro Ezoe; Yasushi Fukazawa; Masahito Hamaya; Shinya Hirakuri; Soojing Hong; Michihiro Horii; Hokuto Inoue; Naoki Isobe; Takeshi Itoh; Naoko Iyomoto; Tuneyoshi Kamae; Daisuke Kasama; Jun Kataoka; Hiroshi Kato; Madoka Kawaharada; Naomi Kawano; Kengo Kawashima; Satoshi Kawasoe; Tetsuichi Kishishita; Takao Kitaguch; Yoshihito Kobayashi; Motohide Kokubun; Jun'ichi Kotoku; Manabu Kouda; Aya Kubota; Yoshikatsu Kuroda; Greg Madejski; Kazuo Makishima; Kazunori Masukama; Yukari Matsumoto; Takefumi Mitani; Ryohei Miyawaki; Tsunefumi Mizuno; Kunishiro Mori; Masanori Mori; Mio Murashima; Toshio Murakami; Kazuhiro Nakazawa; Hisako Niko; Masaharu Nomachi; Yuu Okada; Masanori Ohno; Kousuke Oonuki; Naomi Ota; Hideki Ozawa; Goro Sato; Shingo Shinoda; Masahiko Sugiho; Masaya Suzuki; Koji Taguchi; Hiromitsu Takahashi; Isao Takahashi; Shin'ichiro Takeda; Ken-ichi Tamura; Takayuki Tamura; Takaaki Tanaka; Chiharu Tanihata; Makoto Tashiro; Yukikatsu Terada; Shin'ya Tominaga; Yasunobu Uchiyama; Shin Watanabe; Kazutaka Yamaoka; Takayuki Yanagida; Daisuke Yonetoku, The Hard X-ray Detector (HXD) on board Suzaku covers a wide energy range from 10 keV to 600 keV by the combination of silicon PIN diodes and GSO scintillators. The HXD is designed to achieve an extremely low in-orbit background based on a combination of new techniques, including the concept of a well-type active shield counter. With an effective area of 142 cm(2) at 20 keV and 273 cm(2) at 150 keV, the background level at sea level reached similar to 1 X 10(-5) cts s(-1) cm(-2) keV(-1) at 30 keV for the PIN diodes, and similar to 2 X 10(-5) cts s(-1) cm(-2) keV(-1) at 100 keV, and similar to 7 X 10(-6) cts s(-1) cm(-2) keV(-1) at 200 keV for the phoswich counter. Tight active shielding of the HXD results in a large array of guard counters surrounding the main detector parts. These anti-coincidence counters, made of similar to 4 cm thick BGO crystals, have a large effective area for sub-MeV to MeV gamma-rays. They work as an excellent gamma-ray burst monitor with limited angular resolution (similar to 5 degrees). The on-board signal-processing system and the data transmitted to the ground are also described., 2007年01月, 59, SP1, S35, S51, 10.1093/pasj/59.sp1.S35

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, The X-ray observatory Suzaku, Kazuhisa Mitsuda; Mark Bautz; Hajime Inoue; Richard L. Kelley; Katsuji Koyama; Hideyo Kunieda; Kazuo Makshima; Yoshiaki Ogawara; Robert Petre; Tadayuki Takahashi; Hiroshi Tsunemi; Nicholas E. White; Naohisa Anabuki; Lorella Angelini; Keith Arnaud; Hisamitsu Awaki; Aya Bamba; Kevin Boyce; Gregory V. Brown; Kai-Wing Chan; Jean Cottam; Tadayasu Dotanli; John Doty; Ken Ebisawa; Yuichiro Ezoe; Andrew C. Fabian; Enectali Figueroa; Ryuichi Fujimoto; Yasushi Fukazawa; Tae Furusho; Akihiro Furuzawa; Keith Gendreau; Richard E. Griffiths; Yoshito Haba; Kenji Hamaguchi; Ilana Harrus; Gunther Hasinger; Isamu Hatsukade; Kiyoshi Hayashida; Patrick J. Henry; Junko S. Hiraga; Stephen S. Holt; Ann Hornschemeier; John P. Hughes; Una Hwang; Manabu Ishida; Yoshitaka Ishisaki; Naoki Isobe; Masayuki Itoh; Naoko Iyomoto; Steven M. Kahn; Tuneyoshi Kamae; Hideaki Katagiri; Jun Kataoka; Haruyoshi Katayama; Nobuyuki Kawai; Caroline Kilbourne; Kenzo Kinugasa; Steve Kissel; Shunji Kitamoto; Mitsuhiro Kohama; Takayoshi Kohmura; Motohide Kokubun; Taro Kotani; Jun'ichi Kotoku; Aya Kubota; Greg M. Madejski; Yoshitomo Maeda; Fumiyoshi Makino; Alex Markowitz; Chiho Matsumoto; Hironori Matsumoto; Masaru Matsuoka; Kyoko Matsushita; Dan McCammon; Tatehiko Mihara; Kazutami Misaki; Emi Miyata; Tsunefumi Mizuno; Koji Mori; Hideyuki Mori; Mikio Morii; Harvey Moseley; Koji Mukai; Hiroshi Murakami; Toshio Murakami; Richard Mushotzky; Fumiaki Nagase; Masaaki Namiki; Hitoshi Negoro; Kazubiro Nakazawa; John A. Nousek; Takashi Okajima; Yasushi Ogasaka; Takaya Ohashi; Tai Oshima; Naomi Ota; Masanobu Ozaki; Hideki Ozawa; Arvind N. Parmar; William D. Pence; F. Scott Porter; James N. Reeves; George R. Ricker; Ikuya Sakurai; Wilton T. Sanders; Atsushi Senda; Peter Serlemitsos; Ryo Shibata; Yang Soong; Randall Smith; Motoko Suzuki; Andrew E. Szymkowiak; Hiromitsu Takahashi; Torn Tamagawa; Keisuke Tamura; Takayuki Tamura; Yasuo Tanaka; Makoto Tashiro; Yuzuru Tawara; Yukikatsu Terada; Yuichi Terashima; Hiroshi Tomida; Ken'ichi Torii; Yohko Tsuboi; Masahiro Tsujimoto; Takeshi Go Tsuru; Martin J. L. Turner; Yoshihiro Ueda; Shiro Ueno; Masaru Ueno; Shin'ichiro Uno; Yuji Urata; Shin Watanabe; Norimasa Yamamoto; Kazutaka Yamaoka; Noriko Y. Yamasaki; Koujun Yamashita; Makoto Yamauchi; Shigeo Yamauchi; Tahir Yaqoob; Daisuke Yonetoku; Atsumasa Yoshida, High-sensitivity wide-band X-ray spectroscopy is the key feature of the Suzaku X-ray observatory, launched on 2005 July 10. This paper summarizes the spacecraft, in-orbit performance, operations, and data processing that are related to observations. The scientific instruments, the high-throughput X-ray telescopes, X-ray CCD cameras, non-imaging hard X-ray detector are also described., 2007年01月, 59, SP1, S1, S7, 10.1093/pasj/59.sp1.S1

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• 査読無し, その他, XMM-Newton: The Next Decade, Suzaku Study of hard X-ray Emission from Nearby Galaxy Clusters, OTA Naomi; Kitaguchi, T; Nakazawa, N; Makishima, K; Kawaharada, M; Ota, N; Kokubun, M; Yamasaki, N; Kawano, N; Fukazawa, Y; Sato, K; Ohashi, T; Murase, K; Urata, Y; Tashiro, M; Furusawa, A; Suzaku Team, 2007年
• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, The 7-steps of the data analysis, Yukikatsu Terada; Aya Bamba; Junko S. Hiraga; Naoki Isobe; Aya Kubota; Naomi Ota; Piero Ranalli; Atsushi Senda; Motoko Suzuki; Toru Tamagawa; Yuji Urata; Masanobu Ozaki; Ken Ebisawa; Yoshitaka Ishisaki; Hironori Matsumoto; Izumi Yamagishi; Takayuki Tamura; Koji Mukai; Lorella Angellini; Kenji Hamaguchi, It may seem to be difficult to analyze the Suzaku data, but the data structure and the tools are rather simple. We have constructed the way to process Suzaku FITS data and ftools for over ten years. We have prepared three kinds of manuals to analyze the data; Seven step manual of the XIS and the HXD for beginners, first step manual to walk through the analyses, and the ABC guide as a full manual. In the actual analyses, we have to be careful about events in operation and the limitations in the calibration of instruments. In this paper, the data structure, tools, and manuals with activities of help desks, current status of processing are summarized., 2007年, 169, 169, 312, 315
• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Suzaku survey for non-thermal hard X-ray emission from clusters of galaxies, Kazuhiro Nakazawa; Naomi Kawano; Yasushi Fukazawa; Chihiro Egawa; Takao Kitaguchi; Madoka Kawaharada; Kazuo Makishima; Naomi Ota; Kazuyo Tokoi; Kosuke Sato; Yoshitaka Ishisaki; Takaya Ohashi; Noriko Yamasaki, Status of the Suzaku survey for non-thermal hard X-ray emission from clusters of galaxies is reported. Utilizing the lowest and stable detector background of both the HXD and the XIS instruments, Suzaku achieved high sensitivity for hard X-ray diffuse emission survey. Deep (>= 100 ks) observations of a merging cluster A3376 present an upper limit of similar to 10(-11) erg cm(-2) s(-1) in the 15-50 keV band (Kawano et al. and this work). Other analyses using the HXD (Centaurus and A1060, Kitaguchi et al.) and the XIS (HCG 62, Tokoi et al.) are also briefly summarized., 2007年, 169, 169, 45, 48, 10.1143/PTPS.169.45

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• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Suzaku observation of Abell 2204: Galaxy cluster gas temperature measurement up to the virial radius, Thomas H. Reiprich; Daniel S. Hudson; Oxana-Elena Nenestyan; Kosuke Sato; Yoshitaka Ishisaki; Akio Hoshino; Takaya Ohashi; Naomi Ota; Yutaka Fujita; Guenther Hasinger, Measurements of the intracluster gas temperatures out to large radii, where much of the cluster mass resides, are of the utmost importance for the use of clusters in precision cosmology and for Studies of cluster physics. Previous attempts to measure temperatures at the cluster virial radius have failed. The preliminary results from the Suzaku observation of Abell 2204 reported here show that such measurements appear feasible now for the first time, if care is taken to account for background and PSF effects., 2007年, 169, 169, 33, 36
• 査読無し, 英語, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Absence of bulk motions of the intracluster medium in the Centaurus cluster, Naomi Ota; Yasushi Fukazawa; Andrew C. Fabian; Takehiro Kanemaru; Madoka Kawaharada; Naomi Kawano; Richard L. Kelley; Takao Kitacuchi; Kazuo Makishima; Kyoko Matsusihita; Kouichi Murase; Kazuhiro Nakazawa; Takaya Ohashi; Jeremy S. Sanders; Takayuki Tamura; Yuji Urata, We present results from the Suzaku observations of a nearby cluster, the Centaurus cluster (z = 0.0104). Three pointing observations of the cluster were carried out with the Suzaku XIS in December 2005, and the Doppler shift of the iron K lines was investigated in detail to constrain the bulk velocity of the intracluster medium (ICM) in its core region. From the spectral analysis, no significant velocity difference was detected within calibration uncertainty of +/- 700 kms(-1) over a spatial scale of 50 kpc in the central 240 kpc region. The 90% upper limit on the line-of-sight velocity is < 1400 km s(-1), giving a tighter constraint than the previous measurements. The significant velocity gradients inferred from the previous Chandra observations were not detected in two pairs of regions near the cluster core. These results suggest that the bulk velocity does not largely exceed the thermal velocity of the gas in the central region of the Centaurus cluster. Implications of the present results for the estimation of the cluster mass are discussed., 2007年, 169, 169, 25, 28
• 査読無し, 英語, ESO Astrophysics Symposia, A Suzaku observation of the cluster of galaxies A1060, K. Sato; N. Y. Yamasaki; M. Ishida; Y. Ishisaki; T. Ohashi; T. Kitaguchi; M. Kawaharada; M. Kokubun; K. Makishima; N. Ota; K. Nakazawa; T. Tamura; K. Matsushita; N. Kawano; Y. Fukazawa; J. P. Hughes, We carried out observations of the central and 20′ east offset regions of the cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral=analysis has revealed temperature and abundance profiles of Abell 1060 out to 27′ ≃ 380 h70 -1kpc, which corresponded to ∼0.3 rvir. The temperature decrease of the intra cluster medium from 3.4 keV at the center to 2.2 keV in the outskirt region are clearly observed. Si, S and Fe abundances also decrease by more than 50% from the center to the outer parts, while Mg shows a fairly constant abundance of ∼ 0.7 solar within r < 17′. O shows a lower abundance of ∼0.3 solar in the central region (r < 6′), and indicates a similar feature with Mg, however it is sensitive to the estimated contribution of the Galactic components at the outer annuli (r > 13′). Results on temperature and abundances of Si, S, and Fe are consistent with those derived by XMM-Newton at r < 13′ The formation and metal enrichment of the cluster are discussed based on implications of our results. © 2007 Springer-Verlag Berlin Heidelberg., 2007年, 2007, 398, 400, 10.1007/978-3-540-73484-0_73

  DOI URL
• 査読無し, 英語, ESO Astrophysics Symposia, New results with the XIS onboard suzaku, N. Ota; K. Matsushita, We present new results from the Suzaku XIS observations of two nearby clusters of galaxies, the Centaurus cluster and the Fornax cluster. For the Centaurus cluster, we investigated the Doppler shift of the iron K lines to constrain the bulk velocity of the intracluster medium (ICM) in its core region. We found that there is no significant velocity gradient within the calibration uncertainty: the 90% upper limit on the line-of-sight velocity difference is δ v < 1400 km s-1, providing a tighter constraint than the previous observations. Regarding the Fornax cluster, we studied metal abundances of the ICM out to a large radius. K-lines of O and Mg were clearly resolved and the abundance profiles of O, Mg, Si, S and Fe were derived to high accuracy. The central r < 4′ region shows the Fe, Si, and S abundances to be ∼1 solar, while the Fe and Si abundances drop to about 0.5 solar in the outer region. O/Fe and Mg/Fe are about 0.4-0.5 and 0.7 in unit of the solar ratio, respectively, and do not show any significant radial gradient. Implications of the results on each cluster are briefly discussed. © 2007 Springer-Verlag Berlin Heidelberg., 2007年, 2007, 389, 394, 10.1007/978-3-540-73484-0_71

  DOI URL
• 査読無し, 英語, HEATING VERSUS COOLING IN GALAXIES AND CLUSTERS OF GALAXIES, SPRINGER-VERLAG BERLIN, Chandra and XMM-Newton observations of the group of galaxies HCG 62, T. Ohashi; U. Morita; Y. Ishisaki; N. Y. Yamasaki; N. Ota; N. Kawano; Y. Fukazawa, We present results from Chandra and XMM-Newton observations of the bright group of galaxies HCG 62. The two cavities in the central region show no significant change of temperature compared with that in the surrounding region. We studied radial distributions of temperature and metal abundance. Two temperatures are required in the inner r < 2' (35 kpc) region, and a sharp drop of temperature is seen at r similar to 5' where the gas may not be in hydrostatic equilibrium. The metal distribution suggests that iron and silicon are produced by type Ia supernova in the central galaxy, while galactic winds by type II supernova have caused a wider distribution of oxygen. The pressure due to electrons and magnetic fields is too low to displace the group hot gas, and other pressure contributions from high energy protons or by galaxy-scale dynamical motions are nearly 700 times higher. Detailed accounts are given in [5]., 2007年, 112, +, 10.1007/978-3-540-73484-0_21

  DOI URL
• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるCentaurus銀河団中のガスバルク運動測定, 太田直美; 深沢泰司; 川埜直美; 牧島一夫; 川原田円; 北口貴雄; 佐藤光浩; 松下恭子; 金丸武弘; 浦田裕次; 村瀬弘一; 中澤知洋; 田村隆幸; 大橋隆哉; FABIAN A.C; SANDERS J.S, 2006年08月20日, 2006, 193

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」衛星による銀河団からの非熱的硬X線放射の探査, 川埜直美; 深澤泰司; 北口貴雄; 川原田円; 国分紀秀; 牧島一夫; 中澤知洋; 山崎典子; 太田直美; 佐藤浩介; 大橋隆哉; 村瀬弘一; 浦田裕次; 田代信, 2006年08月20日, 2006, 193

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星で観測された銀河団A 1060の温度構造と重元素分布, 佐藤浩介; 山崎典子; 石崎欣尚; 石田学; 大橋隆哉; 北口貴雄; 川原田円; 国分紀秀; 牧島一夫; 太田直美; 中澤知洋; 田村隆幸; 松下恭子; 川埜直美; 深沢泰司; HUGHES John P, 2006年08月20日, 2006, 192

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるFornax座銀河団の観測―重元素の分布と起源―, 松下恭子; 大橋隆哉; 鶴剛; 深沢泰司; 戸塚都; 山崎典子; 中澤知洋; 田村隆幸; 太田直美; 浦田裕次; 北口貴雄; 牧島一夫; HUGES John, 2006年08月20日, 2006, 193

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• 査読無し, 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 23pSH-11 銀河団中の重元素および銀河の空間分布から探る銀河団の進化(23pSH X線・γ線,宇宙線・宇宙物理領), 川原田 円; 北口 貴雄; 国分 紀秀; 牧島 一夫; 太田 直美; 田村 隆幸; 山崎 典子; 佐藤 浩介; 大橋 隆哉; 松下 恭子; 深沢 泰司; ほか「すざく」チーム, 2006年08月18日, 61, 2, 78, 78
• 査読無し, 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 23pSH-5 「すざく」衛星による銀河団からの硬X線放射の探査(23pSH X線・γ線,宇宙線・宇宙物理領), 北口 貴雄; 川原田 円; 国分 紀秀; 牧島 一夫; 太田 直美; 深沢 泰司; 川埜 直美; 中澤 知洋; 山崎 典子; 佐藤 浩介; 大橋 隆哉; 村瀬 弘一; 浦田 裕次; 田代 信; すざくチーム, 2006年08月18日, 61, 2, 77, 77
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, Chandra observations of SDSS J1004+4112: Constraints on the lensing cluster and anomalous X-ray flux ratios of the quadruply imaged quasar, Naomi Ota; Naohisa Inada; Masamune Oguri; Kazuhisa Mitsuda; Gordon T. Richards; Yasushi Suto; W. N. Brandt; Francisco J. Castander; Ryuichi Fujimoto; Patrick B. Hall; Charles R. Keeton; Robert C. Nichol; Donald P. Schneider; Daniel E. Eisenstein; Joshua A. Frieman; Edwin L. Turner; Takeo Minezaki; Yuzuru Yoshii, We present results from Chandra observations of SDSS J1004+4112, a strongly lensed quasar system with a maximum image separation of 15''. All four bright images of the quasar, as well as resolved X-ray emission originating from the lensing cluster, are clearly detected. The emission from the lensing cluster extends out to approximately 1'5. We measure the bolometric X-ray luminosity and temperature of the lensing cluster to be 4.7; 10(44) ergs s(-1) and 6.4 keV, consistent with the luminosity-temperature relation for distant clusters. The mass estimated from the X-ray observation shows excellent agreement with the mass derived from gravitational lensing. The X-ray flux ratios of the quasar images differ markedly from the optical flux ratios, and the combined X-ray spectrum of the images possesses an unusually strong Fe K alpha emission line, both of which are indicative of microlensing., 2006年08月, 647, 1, 215, 221, 10.1086/505385

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Chandra and XMM-Newton observations of a group of galaxies, HCG 62, Umeyo Morita; Yoshitaka Ishisaki; Noriko Y. Yamasaki; Naomi Ota; Naomi Kawano; Yasushi Fukazawa; Takaya Ohashi, We present results from Chandra and XMM-Newton observations of a bright group of galaxies, HCG 62. There are two cavities at about 30" northeast and 20" southwest of the central galaxy in the Chandra image. The energy spectrum shows no significant change in the cavity compared with that in the surrounding region. The radial X-ray profile is described by the sum of the 3-beta components with core radii of about 2, 10, and 160 kpc. We studied the radial distributions of the temperature and the metal abundance with a joint spectral fit for both data; two temperatures were required in the inner r < 2' (36 kpc) region. A sharp drop of the temperature at r similar to 5' implies a gravitational mass density even lower than the gas density, suggesting that the gas may not be in hydrostatic equilibrium. The Fe and Si abundances are 1-2 solar at the center, and drop to about 0.1 solar at r similar to 10'. The O abundance is less than 0.5 solar, and shows a flatter profile. The observed metal distribution supports the view that iron and silicon are produced by type la supernova (SN Ia) in the central galaxy, while galactic winds by SN II have caused a wide distribution of oxygen. The supporting mechanism of the cavity is discussed. The pressure for the sum of electrons and the magnetic field is too low to displace the hot group gas, and the required pressure due to high-energy protons is nearly 700-times higher than the electron pressure. This leaves the origin of the cavities a puzzle; we also discuss other possible origins of the cavities., 2006年08月, 58, 4, 719, 742, 10.1093/pasj/58.4.719

  DOI URL
• 査読無し, 日本語, 天文月報, X線天文衛星「すざく」による観測速報(4), 伊藤 真之; 馬場 彩; 寺田 幸功; 鶴 剛; 小澤 碧; 松下 恭子; 大橋 隆哉; 太田 直美; 深沢 泰司; 中澤 和洋, 2006年05月20日, 99, 6, 332, 333
• 査読無し, 英語, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, ELSEVIER SCIENCE BV, Ground calibration of the XRS microcalorimeter onboard Suzaku, J Cottam; KR Boyce; GV Brown; R Fujimoto; T Furusho; Y Ishisaki; RL Kelley; CA Kilbourne; D McCammon; K Mitsuda; U Morita; N Ota; FS Porter; T Saab; Y Takei; M Yamamoto, The XRS microcalorimeter was launched in July 2005 as part of the Suzaku mission. It covers the energy band from 0.3 to 10 keV with a nearly constant energy resolution of 6eV and a peak effective area of 200cm(2) at 1.5keV. The XRS will provide unprecedented throughput and resolving power, particularly at high energies and for extended sources. The XRS has undergone extensive instrument level ground calibration prior to integration into the spacecraft. In this presentation, we will describe our pre-launch characterization of the instrument. We will include discussions of the energy scale, the line spread function, and the efficiency of the various components that make up the effective area. Published by Elsevier B.V., 2006年04月, 559, 2, 617, 619, 10.1016/j.nima.2005.12.113

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• 査読無し, 英語, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, ELSEVIER SCIENCE BV, Analysis of the Suzaku/XRS background, CA Kilbourne; KR Boyce; GV Brown; J Cottam; E Figueroa-Feliciano; R Fujimoto; T Furusho; Y Ishisaki; RL Kelley; D McCammon; K Mitsuda; U Morita; FS Porter; N Ota; T Saab; Y Takei; M Yamamoto, Background counts on the XRS calorimeter spectrometer of the Suzaku Observatory (formerly Astro-E2) have several sources, including primary cosmic rays and secondary particles interacting with the pixels and with the silicon structure of the array. Using ground data, we identified the types of correlations between events on different pixels, and between pixel pulses and the signal from the anti-coincidence detector behind the calorimeter. In this paper, we present details of the ground background events and the rejection criteria required to remove them while minimizing deadtime. We also present the in-orbit background measured during the time that XRS was functioning in orbit. Published by Elsevier B.V., 2006年04月, 559, 2, 620, 622, 10.1016/j.nima.2005.12.116

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• 査読無し, 英語, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, ELSEVIER SCIENCE BV, Performance verification of the Suzaku X-ray spectrometer in the flight configuration, N Ota; KR Boyce; GV Brown; J Cottam; R Fujimoto; T Furusho; Y Ishisaki; RL Kelley; CA Kilbourne; D McCammon; K Mitsuda; U Morita; FS Porter; Y Takei; M Yamamoto, The X-ray Spectrometer (XRS) is a high resolution, non-dispersive cryogenic detector on board the X-ray satellite, Suzaku (Astro-E2), which was successfully launched on July 10, 2005. The XRS achieves an energy resolution of 6eV at 6keV (FWHM) and covers a broad energy range of similar to 0.07-10keV. The XRS will enable powerful plasma diagnostics of a variety of astrophysical objects such as the dynamics of gas in clusters of galaxies. The XRS was integrated to the spacecraft in September 2004, and underwent a series of spacecraft tests until April 2005. We describe results of the XRS performance verification in the spacecraft configuration. First, the noise level was extremely low on the spacecraft, and most of the pixels achieved an energy resolution of 5-6 eV at 5.9 keV. Microphonic noise from the mechanical cooler was one of the concerns, but this was not a problem, when the dewar was integrated to the spacecraft and filled with solid neon. To attain the best energy resolution, however, correction of gain drift is mandatory. The XRS has a dedicated calibration pixel for that purpose, and drift correction using the calibration pixel is very effective when the gain variation is due to changes in the similar to 60 mK heat sink temperature. On the other hand, the calibration pixel and the other pixels do not respond in the same way to variations of the helium and neon bath temperatures, and this effect requires further Study. (c) 2006 Elsevier B.V. All rights reserved., 2006年04月, 559, 2, 614, 616, 10.1016/j.nima.2005.12.100

  DOI URL
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, L-X-T relation and related properties of galaxy clusters, N Ota; T Kitayama; K Masai; K Mitsuda, An observational approach is presented to constrain the global structure and evolution of the intracluster medium using the ROSAT and ASCA distant cluster sample. From statistical analysis of the gas density profile and the connection to the L-X-T relation under the beta-model, the scaled gas profile is found to be nearly universal for the outer region, and L-X(> 0.2r(500)) is tightly related to the temperature through T-similar to 3 rather than T-2. On the other hand, a large density scatter exists in the core region, and there is clearly a deviation from the self-similar scaling for clusters with a small core. A link between the core size and the radiative cooling timescale, t(cool), and the analysis of X-ray fundamental plane suggest that tcool is a parameter controlling the gas structure and that the appearance of small cores in regular clusters and may be much connected with the thermal evolution. We derive the luminosity - ambient temperature (T') relation, assuming the universal temperature profile for the clusters with short t(cool), and find that the dispersion around the relation significantly decreases and the slope becomes marginally less steep. We further examined the LX-T beta relation and showed a trend that merging clusters segregate from the regular clusters on the plane. Considering a correlation between tcool and the X-ray morphology, the observational results lead us to draw a phenomenological picture: after a cluster collapses and tcool falls below the age of the universe, the core cools radiatively with quasi-hydrostatic balancing in the gravitational potential, and the central density gradually becomes higher to evolve from an outer-core-dominant cluster, which follows the self-similarity, to an inner-core-dominant cluster., 2006年04月, 640, 2, 673, 690, 10.1086/500294

  DOI URL
• 査読無し, 英語, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, ELSEVIER SCIENCE BV, Performance verification of the Suzaku X-ray spectrometer in the flight configuration, N Ota; KR Boyce; GV Brown; J Cottam; R Fujimoto; T Furusho; Y Ishisaki; RL Kelley; CA Kilbourne; D McCammon; K Mitsuda; U Morita; FS Porter; Y Takei; M Yamamoto, The X-ray Spectrometer (XRS) is a high resolution, non-dispersive cryogenic detector on board the X-ray satellite, Suzaku (Astro-E2), which was successfully launched on July 10, 2005. The XRS achieves an energy resolution of 6eV at 6keV (FWHM) and covers a broad energy range of similar to 0.07-10keV. The XRS will enable powerful plasma diagnostics of a variety of astrophysical objects such as the dynamics of gas in clusters of galaxies. The XRS was integrated to the spacecraft in September 2004, and underwent a series of spacecraft tests until April 2005. We describe results of the XRS performance verification in the spacecraft configuration. First, the noise level was extremely low on the spacecraft, and most of the pixels achieved an energy resolution of 5-6 eV at 5.9 keV. Microphonic noise from the mechanical cooler was one of the concerns, but this was not a problem, when the dewar was integrated to the spacecraft and filled with solid neon. To attain the best energy resolution, however, correction of gain drift is mandatory. The XRS has a dedicated calibration pixel for that purpose, and drift correction using the calibration pixel is very effective when the gain variation is due to changes in the similar to 60 mK heat sink temperature. On the other hand, the calibration pixel and the other pixels do not respond in the same way to variations of the helium and neon bath temperatures, and this effect requires further Study. (c) 2006 Elsevier B.V. All rights reserved., 2006年04月, 559, 2, 614, 616, 10.1016/j.nima.2005.12.100

  DOI URL
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, L-X-T relation and related properties of galaxy clusters, N Ota; T Kitayama; K Masai; K Mitsuda, An observational approach is presented to constrain the global structure and evolution of the intracluster medium using the ROSAT and ASCA distant cluster sample. From statistical analysis of the gas density profile and the connection to the L-X-T relation under the beta-model, the scaled gas profile is found to be nearly universal for the outer region, and L-X(> 0.2r(500)) is tightly related to the temperature through T-similar to 3 rather than T-2. On the other hand, a large density scatter exists in the core region, and there is clearly a deviation from the self-similar scaling for clusters with a small core. A link between the core size and the radiative cooling timescale, t(cool), and the analysis of X-ray fundamental plane suggest that tcool is a parameter controlling the gas structure and that the appearance of small cores in regular clusters and may be much connected with the thermal evolution. We derive the luminosity - ambient temperature (T') relation, assuming the universal temperature profile for the clusters with short t(cool), and find that the dispersion around the relation significantly decreases and the slope becomes marginally less steep. We further examined the LX-T beta relation and showed a trend that merging clusters segregate from the regular clusters on the plane. Considering a correlation between tcool and the X-ray morphology, the observational results lead us to draw a phenomenological picture: after a cluster collapses and tcool falls below the age of the universe, the core cools radiatively with quasi-hydrostatic balancing in the gravitational potential, and the central density gradually becomes higher to evolve from an outer-core-dominant cluster, which follows the self-similarity, to an inner-core-dominant cluster., 2006年04月, 640, 2, 673, 690, 10.1086/500294

  DOI URL
• 査読無し, 日本語, 日本天文学会年会講演予稿集, 「すざく」衛星による銀河団の硬X線放射の探査, 中澤知洋; 深沢泰司; 牧島一夫; 国分紀秀; 太田直美; 川埜直美; 松下恭子; 北口貴雄; 磯部直樹, 2006年02月20日, 2006, 182

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, すざく衛星によるFornax座銀河団の観測, 松下恭子; 大橋隆哉; 鶴剛; 深沢泰司; 戸塚都; 山崎典子; 中澤知洋; 田村隆幸; 太田直美; 磯部直樹; 浦田裕次; 北口貴雄; 佐藤光浩; 牧島一夫, 2006年02月20日, 2006, 178

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• 査読無し, その他, The 9th Asian-Pacific Regional IAU Meeting, held in Nusa Dua, Bali, Indonesia, 26-29 July 2005, High-resolution Observations of Sunyaev-Zel'dovich Effect with the Nobeyama Radio Observatory 45-m Telescope, 太田 直美; Tsuboi, M; Ezawa, H; Matsuo, H; Ota, N; Kuwabara, T; Kasuga, T; NOBEYAMA Sz Effect; Observation Team, 2006年, 243
• 査読無し, その他, The 9th Asian-Pacific Regional IAU Meeting, held in Nusa Dua, Bali, Indonesia, 26-29 July 2005, High-resolution Observations of Sunyaev-Zel'dovich Effect with the Nobeyama Radio Observatory 45-m Telescope, OTA Naomi; Tsuboi, M; Ezawa, H; Matsuo, H; Ota, N; Kuwabara, T; Kasuga, T; NOBEYAMA Sz Effect; Observation Team, 2006年, 243
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Chandra and XMM-Newton observations of a group of galaxies, HCG 62, Umeyo Morita; Yoshitaka Ishisaki; Noriko Y. Yamasaki; Naomi Ota; Naomi Kawano; Yasushi Fukazawa; Takaya Ohashi, We present results from Chandra and XMM-Newton observations of a bright group of galaxies, HCG 62. There are two cavities at about 30" northeast and 20" southwest of the central galaxy in the Chandra image. The energy spectrum shows no significant change in the cavity compared with that in the surrounding region. The radial X-ray profile is described by the sum of the 3-beta components with core radii of about 2, 10, and 160 kpc. We studied the radial distributions of the temperature and the metal abundance with a joint spectral fit for both data; two temperatures were required in the inner r < 2' (36 kpc) region. A sharp drop of the temperature at r similar to 5' implies a gravitational mass density even lower than the gas density, suggesting that the gas may not be in hydrostatic equilibrium. The Fe and Si abundances are 1-2 solar at the center, and drop to about 0.1 solar at r similar to 10'. The O abundance is less than 0.5 solar, and shows a flatter profile. The observed metal distribution supports the view that iron and silicon are produced by type la supernova (SN Ia) in the central galaxy, while galactic winds by SN II have caused a wide distribution of oxygen. The supporting mechanism of the cavity is discussed. The pressure for the sum of electrons and the magnetic field is too low to displace the hot group gas, and the required pressure due to high-energy protons is nearly 700-times higher than the electron pressure. This leaves the origin of the cavities a puzzle; we also discuss other possible origins of the cavities., 2006年08月, 58, 4, 719, 742, 10.1093/pasj/58.4.719

  DOI URL
• 査読無し, 英語, Astronomy and Astrophysics, A uniform X-ray analysis of 79 distant galaxy clusters with ROSAT and ASCA, N. Ota; K. Mitsuda, We present a uniform analysis of the ROSAT HRI and the ASCA GIS/SIS data for 79 distant clusters of galaxies in the redshift range 0.1 < z < 0.82 to study the global structures of the intracluster medium. We have constructed an X-ray catalog consisting of the largest sample of clusters in the redshift range for which pointed X-ray observations were carried out with both the observatories. We determined the emission-weighted X-ray temperatures of the clusters with ASCA, while we studied surface brightness distribution with the ROSAT HRI utilizing the isothermal β model. We investigated the statistical properties and trends for redshift evolution of the X-ray parameters including the temperature, the density profile of the intracluster gas and the gas-mass fraction within r500. We also present correlations of the cluster parameters with the X-ray temperature and with the core radius and compare them with the predictions of the self-similar model, from which we discuss the possible origin of the double structure discovered in the core radius distribution., 2004年12月, 428, 3, 757, 779, 10.1051/0004-6361:20041087

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• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, A uniform X-ray analysis of 79 distant galaxy clusters with ROSAT and ASCA, N Ota; K Mitsuda, We present a uniform analysis of the ROSAT HRI and the ASCA GIS/SIS data for 79 distant clusters of galaxies in the redshift range 0.1<z<0.82 to study the global structures of the intracluster medium. We have constructed an X-ray catalog consisting of the largest sample of clusters in the redshift range for which pointed X-ray observations were carried out with both the observatories. We determined the emission-weighted X-ray temperatures of the clusters with ASCA, while we studied surface brightness distribution with the ROSAT HRI utilizing the isothermal beta model. We investigated the statistical properties and trends for redshift evolution of the X-ray parameters including the temperature, the density profile of the intracluster gas and the gas-mass fraction within r(500). We also present correlations of the cluster parameters with the X-ray temperature and with the core radius and compare them with the predictions of the self-similar model, from which we discuss the possible origin of the double structure discovered in the core radius distribution., 2004年12月, 428, 3, 757, 779, 10.1051/0004-6361:20041087

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Probing warm-hot intergalactic medium associated with the Virgo cluster using an oxygen absorption line, R Fujimoto; Y Takei; T Tamura; K Mitsuda; NY Yamasaki; R Shibata; T Ohashi; N Ota; MD Audley; RL Kelley; CA Kilbourne, To detect a warm-hot intergalactic medium (WHIM) associated with the large-scale structure of the universe, we observed a quasar behind the Virgo cluster with XMM-Newton. With 54 ks exposure, we marginally detected an O VIII Kalpha absorption line at 650.9(-1.9)(+0.8) eV in the RGS spectra, with a statistical confidence of 96.4%. The observed line center energy is consistent with the redshift of M 87, and hence the absorber is associated with the Virgo cluster. From the curve of growth, the O VIII column density was estimated to be greater than or equal to 7 x 10(16) cm(-2). In the EPIC spectra, excess emission was found after evaluating the hot ICM in the Virgo cluster and various background components. We inspected the RASS map of the diffuse soft X-ray background, and confirmed that the level of the north and west regions just outside of the Virgo cluster is consistent with the background model that we used, while that of the east side is significantly higher and the enhancement is comparable with the excess emission found in the EPIC data. We consider a significant portion of the excess emission to be associated with the Virgo cluster, although a possible contribution from the North Polar Spur cannot be excluded. Using the column density and the emission measure and assuming an oxygen abundance of 0.1 and an ionization fraction of 0.4, we estimate that the mean electron density and the line-of-sight distance of the warm-hot gas are less than or equal to 6 x 10(-5) cm(-3) and greater than or equal to 9 Mpc. These strongly suggest detection of a WHIM in a filament associated with the Virgo cluster., 2004年10月, 56, 5, L29, L34, 速報，短報，研究ノート等（学術雑誌）, 10.1093/pasj/56.5.L29

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Chandra observation of a group of galaxies HCG 80: Does the spiral-only group have hot intragroup gas?, N Ota; U Morita; T Kitayama; T Ohashi, We present an analysis of Chandra X-ray observations of a compact group of galaxies, HCG 80 (z = 0.03). The system is a spiral-only group composed of four late-type galaxies, and has a high-velocity dispersion of 309 km s(-1). With high-sensitivity Chandra observations, we searched for diffuse X-ray emission from the intragroup medium (IGM); however, no significant emission was detected. We place a severe upper limit on the luminosity of the diffuse gas as L-X < 6 x 10(40) ergs(-1). On the other hand, significant emission from three of the four members were detected. In particular, we discovered huge halo emission from HCG 80a that extends on a scale of similar to30 kpc perpendicular to the galactic disk, whose X-ray temperature and luminosity were measured to be similar to0.6 keV and similar to4 x 10(40) ergs(-1) in the 0.5-2 keV band, respectively. It is most likely to be an outflow powered by intense starburst activity. Based on the results, we discuss possible reasons for the absence of diffuse X-ray emission in the HCG 80 group, suggesting that the system is subject to galaxy interactions, and is possibly at an early stage of IGM evolution., 2004年10月, 56, 5, 753, 764, 10.1093/pasj/56.5.753

  DOI URL
• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Probing warm-hot intergalactic medium associated with the Virgo cluster using an oxygen absorption line, R Fujimoto; Y Takei; T Tamura; K Mitsuda; NY Yamasaki; R Shibata; T Ohashi; N Ota; MD Audley; RL Kelley; CA Kilbourne, To detect a warm-hot intergalactic medium (WHIM) associated with the large-scale structure of the universe, we observed a quasar behind the Virgo cluster with XMM-Newton. With 54 ks exposure, we marginally detected an O VIII Kalpha absorption line at 650.9(-1.9)(+0.8) eV in the RGS spectra, with a statistical confidence of 96.4%. The observed line center energy is consistent with the redshift of M 87, and hence the absorber is associated with the Virgo cluster. From the curve of growth, the O VIII column density was estimated to be greater than or equal to 7 x 10(16) cm(-2). In the EPIC spectra, excess emission was found after evaluating the hot ICM in the Virgo cluster and various background components. We inspected the RASS map of the diffuse soft X-ray background, and confirmed that the level of the north and west regions just outside of the Virgo cluster is consistent with the background model that we used, while that of the east side is significantly higher and the enhancement is comparable with the excess emission found in the EPIC data. We consider a significant portion of the excess emission to be associated with the Virgo cluster, although a possible contribution from the North Polar Spur cannot be excluded. Using the column density and the emission measure and assuming an oxygen abundance of 0.1 and an ionization fraction of 0.4, we estimate that the mean electron density and the line-of-sight distance of the warm-hot gas are less than or equal to 6 x 10(-5) cm(-3) and greater than or equal to 9 Mpc. These strongly suggest detection of a WHIM in a filament associated with the Virgo cluster., 2004年10月, 56, 5, L29, L34, 速報，短報，研究ノート等（学術雑誌）, 10.1093/pasj/56.5.L29

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Chandra observation of a group of galaxies HCG 80: Does the spiral-only group have hot intragroup gas?, N Ota; U Morita; T Kitayama; T Ohashi, We present an analysis of Chandra X-ray observations of a compact group of galaxies, HCG 80 (z = 0.03). The system is a spiral-only group composed of four late-type galaxies, and has a high-velocity dispersion of 309 km s(-1). With high-sensitivity Chandra observations, we searched for diffuse X-ray emission from the intragroup medium (IGM); however, no significant emission was detected. We place a severe upper limit on the luminosity of the diffuse gas as L-X < 6 x 10(40) ergs(-1). On the other hand, significant emission from three of the four members were detected. In particular, we discovered huge halo emission from HCG 80a that extends on a scale of similar to30 kpc perpendicular to the galactic disk, whose X-ray temperature and luminosity were measured to be similar to0.6 keV and similar to4 x 10(40) ergs(-1) in the 0.5-2 keV band, respectively. It is most likely to be an outflow powered by intense starburst activity. Based on the results, we discuss possible reasons for the absence of diffuse X-ray emission in the HCG 80 group, suggesting that the system is subject to galaxy interactions, and is possibly at an early stage of IGM evolution., 2004年10月, 56, 5, 753, 764, 10.1093/pasj/56.5.753

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Exploring cluster physics with high-resolution Sunyaev-Zel'dovich effect images and X-ray data: The case of the most X-ray-luminous galaxy cluster RX J1347-1145, T Kitayama; E Komatsu; N Ota; T Kuwabara; Y Suto; K Yoshikawa; M Hattori; H Matsuo, Foreseeing the era of high spatial resolution measurements of the Sunyaev-Zel'dovich effect (SZE) in clusters of galaxies, we present a prototype analysis of this sort combined with Chandra X-ray data. It is applied specifically to RX J1347-1145 at z = 0.451, the most X-ray-luminous galaxy cluster known, for which the highest resolution SZE and X-ray images are currently available. We demonstrate that the combined analysis yields a unique probe of complex structures in the intracluster medium, offering determinations of their temperature, density, and line-of-sight extent. For a subclump in RX J1347-1145, previously discovered in our SZE map, the temperature inferred after removing the fore-round and background components is well in excess of 20 keV, indicating that the cluster has recently undergone a violent merger. Excluding the region around this subclump, the SZE signals in submillimeter to centimeter bands (350, 150, and 21 GHz) are all consistent with those expected from Chandra X-ray observations. We further present a temperature deprojection technique based on the SZE and X-ray images, without any knowledge of spatially resolved X-ray spectroscopy. The methodology presented here will be applicable to a statistical sample of clusters available in the future SZE surveys., 2004年02月, 56, 1, 17, 28, 10.1093/pasj/56.1.17

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• 査読無し, 英語, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, OXFORD UNIV PRESS, Exploring cluster physics with high-resolution Sunyaev-Zel'dovich effect images and X-ray data: The case of the most X-ray-luminous galaxy cluster RX J1347-1145, T Kitayama; E Komatsu; N Ota; T Kuwabara; Y Suto; K Yoshikawa; M Hattori; H Matsuo, Foreseeing the era of high spatial resolution measurements of the Sunyaev-Zel'dovich effect (SZE) in clusters of galaxies, we present a prototype analysis of this sort combined with Chandra X-ray data. It is applied specifically to RX J1347-1145 at z = 0.451, the most X-ray-luminous galaxy cluster known, for which the highest resolution SZE and X-ray images are currently available. We demonstrate that the combined analysis yields a unique probe of complex structures in the intracluster medium, offering determinations of their temperature, density, and line-of-sight extent. For a subclump in RX J1347-1145, previously discovered in our SZE map, the temperature inferred after removing the fore-round and background components is well in excess of 20 keV, indicating that the cluster has recently undergone a violent merger. Excluding the region around this subclump, the SZE signals in submillimeter to centimeter bands (350, 150, and 21 GHz) are all consistent with those expected from Chandra X-ray observations. We further present a temperature deprojection technique based on the SZE and X-ray images, without any knowledge of spatially resolved X-ray spectroscopy. The methodology presented here will be applicable to a statistical sample of clusters available in the future SZE surveys., 2004年02月, 56, 1, 17, 28, 10.1093/pasj/56.1.17

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• 査読無し, 日本語, 日本天文学会年会講演予稿集, 野辺山45m望遠鏡を用いた銀河団のSunyaev‐Zel’dovich効果の撮像観測, 桑原健; 須藤靖; 吉川耕司; 太田直美; 坪井昌人; 松尾宏; 江澤元; 宮崎敦史; 杉山直; 藤田裕; 春日隆; 北山哲; 小松英一郎; 服部誠; 松下聡樹, 2004年, 2004, 204

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• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, Chandra analysis and mass estimation of the lensing cluster of galaxies Cl 0024+17, N Ota; E Pointecouteau; M Hattori; K Mitsuda, We present a detailed analysis of Chandra X-ray observations of the lensing cluster of galaxies Cl 0024+17 at z = 0.395. We found that the radial temperature profile is consistent with being isothermal out to similar to600 kpc and that the average X-ray temperature is 4.47(-0.54)(+0.83) keV. The X-ray surface brightness profile is represented by the sum of extended emission centered at the central bright elliptical galaxy with a small core of 50 kpc and more extended emission that can be well described by a spherical beta-model with a core radius of about 210 kpc. Assuming the X-ray-emitting gas to be in hydrostatic equilibrium, we estimated the X-ray mass within the arc radius and found that it is significantly smaller than the strong lensing mass by a factor of about 2-3. We detected a strong redshifted iron K line in the X-ray spectrum from the cluster for the first time and found the metal abundance to be 0.76(-0.31)(+0.37) solar., 2004年01月, 601, 1, 120, 132, 10.1086/380438

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• 査読無し, その他, The Astrophysical Journal,, Chandra Analysis and Mass Estimation of the Lensing Cluster of Galaxies Cl 0024+17, OTA Naomi; Ota, N; Pointecouteau, E; Hattori, M; Mitsuda, K, 2004年, 601, 1, 120, 132, 10.1086/380438

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• 査読無し, その他, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, Chandra Analysis and Mass Estimation of the Lensing Cluster CL0024+17, 太田 直美; Ota, N; Hattori, M; Pointecouteau, E; Mitsuda, K, 2003年, 141, 10.1086/380438

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• 査読無し, その他, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, Chandra Detection of an Extended Emission Around the Edge-On Galaxy NGC 55, 太田 直美; Oshima, T; Mitsuda, K; Ota, N; Yamasaki, N. Y, 2003年, 33
• 査読無し, 英語, ASTRONOMISCHE NACHRICHTEN, WILEY-V C H VERLAG GMBH, A uniform X-ray analysis of 79 distant clusters of galaxies, N Ota; K Mitsuda, 2003年, 324, 1-2, 172, 172
• 査読無し, その他, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, Chandra Analysis and Mass Estimation of the Lensing Cluster CL0024+17, OTA Naomi; Ota, N; Hattori, M; Pointecouteau, E; Mitsuda, K, 2003年, 141, 10.1086/380438

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• 査読無し, その他, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, Chandra Detection of an Extended Emission Around the Edge-On Galaxy NGC 55, OTA Naomi; Oshima, T; Mitsuda, K; Ota, N; Yamasaki, N. Y, 2003年, 33
• 査読無し, その他, Astronomische Nachrichten, A uniform X-ray analysis of 79 distant clusters of galaxies, OTA Naomi; Ota, N; Mitsuda, K, 2003年, 324, 1-2, 172
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, X-ray study of 79 distant clusters of galaxies: Discovery of two classes of cluster size, N Ota; K Mitsuda, We have performed a uniform analysis of 79 clusters of galaxies with the ROSAT/High Resolution Imager (HRI) and ASCA to study the X-ray structure and evolution of clusters in the redshift range 0.1 < z < 1. We determined the average X-ray temperatures and the bolometric luminosities with ASCA and the spatial distributions of the X-ray brightness with ROSAT/HRI by utilizing the isothermal beta model. We do not find any significant redshift dependence in the X-ray parameters, including the temperature, beta-model parameters, and the central electron density. Among the parameters, the core radius shows the largest cluster-to-cluster dispersions. We discovered that the histogram of the core radius shows two peaks at 60 and 220 kpc. If we divide the cluster samples into two subgroups corresponding to the two peaks in the core radius distribution, they show differences in the X-ray and optical morphologies and in the X-ray luminosity-temperature relation. From these observational results, we suggest that the clusters are divided into at least two subgroups according to the core radius., 2002年03月, 567, 1, L23, L26, 10.1086/339852

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• 査読無し, その他, New Trends in Theoretical and Observational Cosmology, Proceedings of the 5th RESCEU International Symposium, Two Classes of Cluster Size and the Connection to the L-T Relation, 太田 直美; Ota, N; Mitsuda, K, 2002年, 337
• 査読無し, 英語, TRACING COSMIC EVOLUTION WITH GALAXY CLUSTERS, PROCEEDINGS, ASTRONOMICAL SOC PACIFIC, Cluster structure in a large number of ROSAT and ASCA clusters, N Ota; K Mitsuda, We have performed systematic analysis on X-ray structures of eighty distant clusters of galaxies in the redshift range 0.1 < z < 1. We find that (1) cluster parameters such as temperature, core radius, 8 do not show significant redshift dependence, (2) the core radius shows a double-peaked distribution in its histogram, and (3) the gas-mass ratio is 0.28 +/- 0.10 h(50)(-3/2)., 2002年, 268, 423, 424
• 査読無し, その他, The Proceedings of the IAU 8th Asian-Pacific Regional Meeting, Chandra Detection of an Extended Emission around the Edge-on Galaxy NGC 55, 太田 直美; Oshima, T; Mitsuda, K; Ota, N; Yamasaki, N, 2002年, II, 287, 288
• 査読無し, その他, The Astrophysical Journal, X-Ray Study of 79 Distant Clusters of Galaxies: Discovery of Two Classes of Cluster Size, OTA Naomi; Ota, N; Mitsuda, K, 2002年, 567, 1, L23-L26, 10.1086/339852

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• 査読無し, その他, New Trends in Theoretical and Observational Cosmology, Proceedings of the 5th RESCEU International Symposium, Two Classes of Cluster Size and the Connection to the L-T Relation, OTA Naomi; Ota, N; Mitsuda, K, 2002年, 337
• 査読無し, 英語, TRACING COSMIC EVOLUTION WITH GALAXY CLUSTERS, PROCEEDINGS, ASTRONOMICAL SOC PACIFIC, Cluster structure in a large number of ROSAT and ASCA clusters, N Ota; K Mitsuda, We have performed systematic analysis on X-ray structures of eighty distant clusters of galaxies in the redshift range 0.1 < z < 1. We find that (1) cluster parameters such as temperature, core radius, 8 do not show significant redshift dependence, (2) the core radius shows a double-peaked distribution in its histogram, and (3) the gas-mass ratio is 0.28 +/- 0.10 h(50)(-3/2)., 2002年, 268, 423, 424
• 査読無し, その他, The Proceedings of the IAU 8th Asian-Pacific Regional Meeting, Chandra Detection of an Extended Emission around the Edge-on Galaxy NGC 55, OTA Naomi; Oshima, T; Mitsuda, K; Ota, N; Yamasaki, N, 2002年, II, 287, 288
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, ASCA observation of the lensed blazar PKS 1830-211: An implication of X-ray microlensing, T Oshima; K Mitsuda; N Ota; A Yonehara; M Hattori; T Mihara; Y Sekimoto, We present ASCA observations of the gravitationally lensed blazar PKS 1830-211. Intensity variations of about 10% and spectral variations were detected in the eight observations made at intervals of about 5 days. The spectral variations can be described by a change of absorption column density if we represent the spectrum with a single power-law model. However, it is more likely that the spectrum consists of two spectral components with different absorptions and that their intensity ratio varies. The column densities of the two components are consistent with the column densities of the two lensed images. However, the intensity ratio is different by a factor of 7.4 from the magnification ratio of the two lensed images. We suggest that the discrepancy is most likely due to X-ray microlensing, among several other possibilities. We estimate that the size of the X-ray emission region must be smaller than similar to3 x 10(14) cm in order to explain the observed microlensing magnification., 2001年04月, 551, 2, 929, 933, 10.1086/320246

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• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, ASCA observation of the lensed blazar PKS 1830-211: An implication of X-ray microlensing, T Oshima; K Mitsuda; N Ota; A Yonehara; M Hattori; T Mihara; Y Sekimoto, We present ASCA observations of the gravitationally lensed blazar PKS 1830-211. Intensity variations of about 10% and spectral variations were detected in the eight observations made at intervals of about 5 days. The spectral variations can be described by a change of absorption column density if we represent the spectrum with a single power-law model. However, it is more likely that the spectrum consists of two spectral components with different absorptions and that their intensity ratio varies. The column densities of the two components are consistent with the column densities of the two lensed images. However, the intensity ratio is different by a factor of 7.4 from the magnification ratio of the two lensed images. We suggest that the discrepancy is most likely due to X-ray microlensing, among several other possibilities. We estimate that the size of the X-ray emission region must be smaller than similar to3 x 10(14) cm in order to explain the observed microlensing magnification., 2001年04月, 551, 2, 929, 933, 10.1086/320246

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• 査読無し, 英語, GRAVITATIONAL LENSING: RECENT PROGRESS AND FUTURE GOALS, ASTRONOMICAL SOC PACIFIC, Iron emission line from the galaxy cluster including the lensing radio galaxy 3C220.1 at z=0.62, N Ota; K Mitsuda; M Hattori; T Mihara, 2001年, 237, 333, 334
• 査読無し, その他, The Astrophysical Journal, Detection of an Iron Emission Feature from the Lensed Broad Absorption Line QSO H1413+117 at z = 2.56, 太田 直美; Oshima, T; Mitsuda, K; Fujimoto, R; Iyomoto, N; Futamoto, K; Hattori, M; Ota, N; Mori, K; Ikebe, Y; Miralles, J. M; Kneib, J.-P, 2001年, 563, 2, L103-L106, 10.1086/338653

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• 査読無し, 英語, NEW CENTURY OF X-RAY ASTRONOMY, ASTRONOMICAL SOC PACIFIC, X-ray study of distant clusters of galaxies: Structure and evolution, N Ota; K Mitsuda, We have performed systematic analysis on X-ray structures of eighty distant clusters of galaxies in the redshift range 0.1 < z < 1. We find that (1) cluster parameters such as temperature, core radius, and beta do not show significant redshift dependence, (2) the core radius shows a double-peaked distribution in its histogram, and (3) the gas-mass ratio is 0.28 +/- 0.10., 2001年, 251, 478, 479
• 査読無し, 英語, NEW CENTURY OF X-RAY ASTRONOMY, ASTRONOMICAL SOC PACIFIC, Probing distant universe X-ray sources with gravitational lensing, T Oshima; K Mitsuda; N Ota; K Futamoto; M Hattori; A Yonehara; Y Sekimoto; T Mihara; Y Ikebe; JP Kneib; JM Miralles, We report the detection of the gravitationally lensed BALQSO H1413+117 at z=2.56, with the 40 ks Chandra ACIS-S observation. The X-ray image contains quadruply lensed images, however the flux ratios of the four images differ from the optical values by a factor of similar to5. We obtained the luminosity of 3.9x10(44) ergs/s for the QSO, and an upperlimit of 3.7x10(43) ergs/s for the possible lens object. The X-ray energy spectrum requires a strong BAL absorption feature with a hydrogen column density of 2.4(-1.2)(+1.5) x 10(23) cm(-2) at z=2.55(-0.18)(+0.27), consistent with the QSO redshift. In addition, a strong emission line at 6.21 +/- 0.16 keV with the equivalent width of 960(-480)(+1400) eV at the QSO rest frame, suggests that most of the direct component from the central engine is blocked by the BAL flow thus making the scattered component dominant., 2001年, 251, 476, 477
• 査読無し, 英語, NEW CENTURY OF X-RAY ASTRONOMY, ASTRONOMICAL SOC PACIFIC, Structure of clusters of galaxies inferred from a large sample of ROSAT and ASCA observations, K Mitsuda; N Ota, The core radius distribution and its relation to the lummosity-temperature (L-X - T) relation of clusters of galaxies are discussed based on 79 clusters observed with ROSAT and ASCA. We find that the core radius distribution show high concentrations at similar to 60 and similar to 220 kpc. We also find that the core radius does not show strong correlation with the virial radius, and that the normalization of the L-X - T relation depends on the core radius. These suggest that the core radius is determined by some physical processes in the cluster central region, almost independent of the virial mass. Assuming beta profiles for cluster gas distribution, we show that the model in which the core radius takes one of two typical values can consistently explain the observed L-X - T relation. The model L-X - T relation is expected to show small dependency on the cluster collapse epochs., 2001年, 251, 164, 167
• 査読無し, 英語, GRAVITATIONAL LENSING: RECENT PROGRESS AND FUTURE GOALS, ASTRONOMICAL SOC PACIFIC, Iron emission line from the galaxy cluster including the lensing radio galaxy 3C220.1 at z=0.62, N Ota; K Mitsuda; M Hattori; T Mihara, 2001年, 237, 333, 334
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, Detection of an iron emission feature from the lensed broad absorption line QSO H1413+117 at z=2.56, T Oshima; K Mitsuda; R Fujimoto; N Iyomoto; K Futamoto; M Hattori; N Ota; K Mori; Y Ikebe; JM Miralles; JP Kneib, We present the X-ray energy spectrum of the lensed broad absorption line QSO H1413+117 (the Cloverleaf) at z = 2.56 observed with the Chandra X-ray observatory. We detected 293 photons in a 40 ks Advanced CCD Imaging Spectrometer (ACIS-S) observation. The X-ray image consists of four lensed image components, thus the photons are from the lensed QSO itself. The overall spectrum can be described with a power-law function heavily absorbed by neutral matter at a redshift consistent with the QSO redshift. This supports the idea that intrinsic absorption is significant for BAL QSOs. The spectral fit significantly (99% confidence) improves when we include an emission line. The centroid energy and intrinsic width (Gaussian sigma) of the line are 6.21 +/- 0.16 keV and 220(-130+)(270) eV (90% errors), respectively, in the QSO rest frame, assuming the absorbed power law as the continuum. The equivalent width of the line in the QSO rest frame is 960(-480)(+1400) eV. We suggest that the large equivalent width, the centroid energy, and the line broadness can be explained by iron K emission arising from X-ray reprocessing in the BAL flow, assuming it has a conical thin-sheet structure., 2001年12月, 563, 2, L103, L106, 10.1086/338653

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• 査読無し, その他, New Century of X-ray Astronomy, ASP Conference Proceedings, X-ray Study of Distant Clusters of Galaxies: Structure and Evolution, OTA Naomi; Ota, N; Mitsuda, K, 2001年, 251, 478
• 査読無し, 英語, NEW CENTURY OF X-RAY ASTRONOMY, ASTRONOMICAL SOC PACIFIC, Probing distant universe X-ray sources with gravitational lensing, T Oshima; K Mitsuda; N Ota; K Futamoto; M Hattori; A Yonehara; Y Sekimoto; T Mihara; Y Ikebe; JP Kneib; JM Miralles, We report the detection of the gravitationally lensed BALQSO H1413+117 at z=2.56, with the 40 ks Chandra ACIS-S observation. The X-ray image contains quadruply lensed images, however the flux ratios of the four images differ from the optical values by a factor of similar to5. We obtained the luminosity of 3.9x10(44) ergs/s for the QSO, and an upperlimit of 3.7x10(43) ergs/s for the possible lens object. The X-ray energy spectrum requires a strong BAL absorption feature with a hydrogen column density of 2.4(-1.2)(+1.5) x 10(23) cm(-2) at z=2.55(-0.18)(+0.27), consistent with the QSO redshift. In addition, a strong emission line at 6.21 +/- 0.16 keV with the equivalent width of 960(-480)(+1400) eV at the QSO rest frame, suggests that most of the direct component from the central engine is blocked by the BAL flow thus making the scattered component dominant., 2001年, 251, 476, 477
• 査読無し, その他, New Century of X-ray Astronomy, ASP Conference Proceedings, Structure of Clusters of Galaxies Inferred from a Large Sample of ROSAT and ASCA Observations, OTA Naomi; Mitsuda, K; Ota, N, 2001年, 251, 164
• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, X-ray observations and mass determinations in the cluster of galaxies C10024+17, G Soucail; N Ota; H Bohringer; O Czoske; M Hattori; Y Mellier, We present a detailed analysis of the mass distribution in the rich and distant cluster of galaxies C10024+17. X-ray data come from both a deep ROSAT HRI image of the field (Bohringer et al. 2000) and ASCA spectral data. Using a wide field CCD image of the cluster, we optically identify all the faint X-ray sources, whose counts are compatible with deep X-ray number counts. In addition we marginally detect the X-ray counter-part of the gravitational shear perturbation detected by Bonnet et al. (1994) at a 2.5 sigma level. A careful spectral analysis of ASCA data is also presented. In particular, we extract a low resolution spectrum of the cluster free from the contamination by a nearby point source located 1.2 arcmin from the center. The X-ray temperature deduced from this analysis is T(X) = 5.7(-2.1)(+4.9) keV at the 90% confidence level. The comparison between the mass derived from a standard X-ray analysis and from other methods such as the Virial Theorem or the gravitational lensing effect lead to a mass discrepancy of a factor 1.5 to 3, We discuss all the possible sources of uncertainties in each method of mass determination and give some indications on the way to reduce them. A complementary study of optical data is in progress and may solve the X-ray/optical discrepancy through a better understanding of the dynamics of the cluster., 2000年03月, 355, 2, 433, 442
• 査読無し, 英語, ASTRONOMY & ASTROPHYSICS, EDP SCIENCES S A, X-ray observations and mass determinations in the cluster of galaxies C10024+17, G Soucail; N Ota; H Bohringer; O Czoske; M Hattori; Y Mellier, We present a detailed analysis of the mass distribution in the rich and distant cluster of galaxies C10024+17. X-ray data come from both a deep ROSAT HRI image of the field (Bohringer et al. 2000) and ASCA spectral data. Using a wide field CCD image of the cluster, we optically identify all the faint X-ray sources, whose counts are compatible with deep X-ray number counts. In addition we marginally detect the X-ray counter-part of the gravitational shear perturbation detected by Bonnet et al. (1994) at a 2.5 sigma level. A careful spectral analysis of ASCA data is also presented. In particular, we extract a low resolution spectrum of the cluster free from the contamination by a nearby point source located 1.2 arcmin from the center. The X-ray temperature deduced from this analysis is T(X) = 5.7(-2.1)(+4.9) keV at the 90% confidence level. The comparison between the mass derived from a standard X-ray analysis and from other methods such as the Virial Theorem or the gravitational lensing effect lead to a mass discrepancy of a factor 1.5 to 3, We discuss all the possible sources of uncertainties in each method of mass determination and give some indications on the way to reduce them. A complementary study of optical data is in progress and may solve the X-ray/optical discrepancy through a better understanding of the dynamics of the cluster., 2000年03月, 355, 2, 433, 442
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, Detection of iron emission lines from the galaxy cluster including the radio galaxy 3C 220.1 at z=0.62, N Ota; K Mitsuda; M Hattori; T Mihara, We have detected an emission-line feature at 4 keV in the X-ray emission from a sky region including the distant radio galaxy 3C 220.1 (z = 0.62) obtained with ASCA. The line energy is 6.1-7.0 keV (90% confidence) in the rest frame of 3C 220.1. Within the present statistics, the observed spectra are consistent with two different models: a nonthermal model consisting of a power-law continuum plus a 6.4 keV iron emission line and a Raymond-Smith thin thermal emission model of kT similar to 6 keV with a metal abundance of similar to 0.5 solar. However, because of the large (similar to 500 eV) equivalent width of the line, a significant fraction of the X-ray emission is likely to arise from the hot intracluster gas associated with the galaxy cluster that includes 3C 220.1. The spectral parameters of the thermal emission are consistent with the luminosity-temperature relation of nearby clusters., 2000年02月, 530, 1, 172, 176
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, UNIV CHICAGO PRESS, Detection of iron emission lines from the galaxy cluster including the radio galaxy 3C 220.1 at z=0.62, N Ota; K Mitsuda; M Hattori; T Mihara, We have detected an emission-line feature at 4 keV in the X-ray emission from a sky region including the distant radio galaxy 3C 220.1 (z = 0.62) obtained with ASCA. The line energy is 6.1-7.0 keV (90% confidence) in the rest frame of 3C 220.1. Within the present statistics, the observed spectra are consistent with two different models: a nonthermal model consisting of a power-law continuum plus a 6.4 keV iron emission line and a Raymond-Smith thin thermal emission model of kT similar to 6 keV with a metal abundance of similar to 0.5 solar. However, because of the large (similar to 500 eV) equivalent width of the line, a significant fraction of the X-ray emission is likely to arise from the hot intracluster gas associated with the galaxy cluster that includes 3C 220.1. The spectral parameters of the thermal emission are consistent with the luminosity-temperature relation of nearby clusters., 2000年02月, 530, 1, 172, 176
• 査読無し, 日本語, 日本天文学会年会講演予稿集, ASTRO‐E衛星搭載用硬X線検出器(HXD)の地上最終キャリブレーション(2), 杉保昌彦; 釜江常好; 牧島一夫; 田代信; 深沢泰司; 国分紀秀; 中澤知洋; 磯部直樹; 松本縁; 江副祐一郎; 高橋勲; 高橋忠幸; 村上敏夫; 太田直美; 谷畑千春; 内山泰伸; 米徳大輔; 渡辺伸, 2000年, 2000, 178

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• 査読無し, 英語, BROAD BAND X-RAY SPECTRA OF COSMIC SOURCES, PERGAMON PRESS LTD, Detection of iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1, N Ota; K Mitsuda; M Hattori; T Mihara, We detected an emission line feature at. 4 keV in the X-ray spectrum of a sky region including the distant radio galaxy 3C220.1(z = 0.62) obtained with ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of 3C220.1. Within the present statistics, the observed spectra are consistent with two different models; a non-thermal model consisting of a power-law continuum plus a 6.4 keV iron emission line, and a Raymond-Smith thin-thermal emission model of kT similar to 6 keV with a metal abundance of similar to 0.5 solar. However, the large (similar to 500 eV) equivalent width of the line indicates that a significant fraction of the X-ray emission is likely to arise from the hot intracluster gas associating the galaxy cluster including 3C220.1, The spectral parameters of the thermal emission are consistent with the luminosity-temperature relation of nearby clusters and the mass estimates from the giant luminous arc. (C) 2000 COSPAR. Published by Elsevier Science Ltd., 2000年, 25, 3-4, 789, 792
• 査読無し, 英語, BROAD BAND X-RAY SPECTRA OF COSMIC SOURCES, PERGAMON PRESS LTD, Detection of iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1, N Ota; K Mitsuda; M Hattori; T Mihara, We detected an emission line feature at. 4 keV in the X-ray spectrum of a sky region including the distant radio galaxy 3C220.1(z = 0.62) obtained with ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of 3C220.1. Within the present statistics, the observed spectra are consistent with two different models; a non-thermal model consisting of a power-law continuum plus a 6.4 keV iron emission line, and a Raymond-Smith thin-thermal emission model of kT similar to 6 keV with a metal abundance of similar to 0.5 solar. However, the large (similar to 500 eV) equivalent width of the line indicates that a significant fraction of the X-ray emission is likely to arise from the hot intracluster gas associating the galaxy cluster including 3C220.1, The spectral parameters of the thermal emission are consistent with the luminosity-temperature relation of nearby clusters and the mass estimates from the giant luminous arc. (C) 2000 COSPAR. Published by Elsevier Science Ltd., 2000年, 25, 3-4, 789, 792
• 査読無し, 英語, Advances in Space Research, Elsevier Ltd, Detection of iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1, Naomi Ota; Kazuhisa Mitsuda; Makoto Hattori; Tatehiro Mihara, We detected an emission line feature at 4 keV in the X-ray spectrum of a sky region including the distant radio galaxy 3C220.1(z = 0.62) obtained with ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of 3C220.1. Within the present statistics, the observed spectra are consistent with two different models a non-thermal model consisting of a power-law continuum plus a 6.4 keV iron emission line, and a Raymond-Smith thin-thermal emission model of kT ∼ 6 keV with a metal abundance of ∼ 0.5 solar. However, the large (∼ 500 eV) equivalent width of the line indicates that a significant fraction of the X-ray emission is likely to arise from the hot intracluster gas associating the galaxy cluster including 3C220.1. The spectral parameters of the thermal emission are consistent with the luminosity-temperature relation of nearby clusters and the mass estimates from the giant luminous arc. © 2000 COSPAR. Published by Elsevier Science Ltd., 2000年, 25, 3-4, 789, 792, 10.1016/S0273-1177(99)00841-8

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• 査読無し, 英語, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY X, SPIE-INT SOC OPTICAL ENGINEERING, Preflight performance of the ASTRO-E hard x-ray detector, C Tanihata; J Kataoka; T Murakami; N Ota; H Ozawa; T Takahashi; T Tamura; Y Uchiyama; S Watanabe; K Yamaoka; D Yonetoku; Y Ezoe; Y Fukazawa; N Isobe; N Iyomoto; T Kamae; M Kokubun; J Kotoku; A Kubota; K Makishima; Y Matsumoto; T Mizuno; K Nakazawa; T Onishi; M Sugiho; Takahashi, I; M Tanaka; M Tashiro; Y Terada; M Nomachi; A Yoshida; M Hamaya; M Horii; K Taguchi; N Morita; Odagi, I; K Sato; Y Tanaka; K Mori, The Hard X-ray Detector (HXD) is one of the three experiments of the Astro-E mission, the fifth Japanese X-ray satellite devoted to studies of high energy phenomena in the universe in the X-ray to soft gamma-ray region.(1-3) Prepared for launch at the beginning of 2000 via the newly developed M-V launch vehicle of the Institute of Space and Astronautical Science, the Astro-E is to be thrown into a near-circular orbit of 550 km altitude, with an inclination of 31 degrees. The flight model has been finished assembled this year, and we carried out various tests to verify the performance. We acquired the background spectrum at sea level, and confirmed that our system is operating effectively in reducing the background level. The HXD will observe photons in the energy range of 10-600 keV, and the calculations based on the preflight calibration suggest that the HXD will have the highest sensitivity ever achieved in this energy range. We also verified that our electronic system will maintain its performance against charged particle events expected in orbit., 1999年, 3765, 645, 663
• 査読無し, 英語, ASTRONOMISCHE NACHRICHTEN, WILEY-V C H VERLAG GMBH, Detection of Iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1, N Ota; K Mitsuda; M Hattori; T Mihara, 1999年, 320, 4-5, 295, 295
• 査読無し, 英語, ASTRONOMISCHE NACHRICHTEN, WILEY-V C H VERLAG GMBH, X-ray detection from the distant cluster of galaxies around 3CR184, T Mihara; K Nogami; M Hattori; K Mitsuda; N Ota, 1999年, 320, 4-5, 293, 293
• 査読無し, 英語, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY X, SPIE-INT SOC OPTICAL ENGINEERING, Preflight performance of the ASTRO-E hard x-ray detector, C Tanihata; J Kataoka; T Murakami; N Ota; H Ozawa; T Takahashi; T Tamura; Y Uchiyama; S Watanabe; K Yamaoka; D Yonetoku; Y Ezoe; Y Fukazawa; N Isobe; N Iyomoto; T Kamae; M Kokubun; J Kotoku; A Kubota; K Makishima; Y Matsumoto; T Mizuno; K Nakazawa; T Onishi; M Sugiho; Takahashi, I; M Tanaka; M Tashiro; Y Terada; M Nomachi; A Yoshida; M Hamaya; M Horii; K Taguchi; N Morita; Odagi, I; K Sato; Y Tanaka; K Mori, The Hard X-ray Detector (HXD) is one of the three experiments of the Astro-E mission, the fifth Japanese X-ray satellite devoted to studies of high energy phenomena in the universe in the X-ray to soft gamma-ray region.(1-3) Prepared for launch at the beginning of 2000 via the newly developed M-V launch vehicle of the Institute of Space and Astronautical Science, the Astro-E is to be thrown into a near-circular orbit of 550 km altitude, with an inclination of 31 degrees. The flight model has been finished assembled this year, and we carried out various tests to verify the performance. We acquired the background spectrum at sea level, and confirmed that our system is operating effectively in reducing the background level. The HXD will observe photons in the energy range of 10-600 keV, and the calculations based on the preflight calibration suggest that the HXD will have the highest sensitivity ever achieved in this energy range. We also verified that our electronic system will maintain its performance against charged particle events expected in orbit., 1999年, 3765, 645, 663
• 査読無し, 英語, ASTRONOMISCHE NACHRICHTEN, WILEY-V C H VERLAG GMBH, Detection of Iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1, N Ota; K Mitsuda; M Hattori; T Mihara, 1999年, 320, 4-5, 295, 295
• 査読無し, 英語, ASTRONOMISCHE NACHRICHTEN, WILEY-V C H VERLAG GMBH, X-ray detection from the distant cluster of galaxies around 3CR184, T Mihara; K Nogami; M Hattori; K Mitsuda; N Ota, 1999年, 320, 4-5, 293, 293
• 査読無し, 英語, ASTROPHYSICAL JOURNAL, IOP PUBLISHING LTD, ASCA observations of the lensing clusters CL 0500-24, CL 2244-02, and A370: Mass determinations and comparisons, N Ota; K Mitsuda; Y Fukazawa, ASCA observations of three gravitational lensing clusters, CL 0500-24, CL 2244-02, and A370, are presented. The X-ray temperatures of the three clusters are determined, respectively, at 7.2 (5.4-10.9), 6.5 (5.2-8.3), and 6.6 (5.7-7.7) keV (90% error), while the X-ray luminosities are determined to be 1.7, 1.3, and 8.3 x 10(44) ergs s(-1) in the 2-10 keV band. We also obtained significant constraints on the surface brightness profile assuming the beta-model and the King model (i.e., the beta-model with beta = 1) profiles. The mass of the cluster estimated from these X-ray data is smaller by a factor of 2-3 than the mass estimated from lens models for two of the clusters, CL 0500-24 and A370, while the two independent mass estimates are consistent with each other for CL 2244-02. We suspect that the major cause of mass discrepancy of CL 0500-24 and A370 is in the projection effect of substructures of these clusters., 1998年03月, 495, 1, 170, 178, 10.1086/305266

  DOI URL
• 査読無し, 英語, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY IX, SPIE-INT SOC OPTICAL ENGINEERING, The electronic system for the Astro-E Hard X-ray Detector, T Takahashi; M Nomachi; Y Fukazawa; M Tashiro; H Ezawa; M Hamaya; M Horii; N Isobe; N Iyomoto; J Kataoka; T Kamae; G Kawaguchi; H Kubo; S Kubo; A Kubota; M Kokubun; K Makishima; K Matsuzaki; Y Matsumoto; T Mizuno; K Mori; N Morita; T Murakami; K Nakazawa; H Obayashi; Odagi, I; T Onishi; N Ota; H Ozawa; K Sato; K Sato; M Sugiho; M Sugizaki; K Taguchi; T Tamura; Y Tanaka; C Tanihata; Y Terada; Y Uchiyama; K Yamaoka; A Yoshida, The Hard X-ray Detector (HXD) is one of three instruments on the fifth Japanese X-ray astronomy satellite. Astro-E, scheduled for launch in 2000. The sensitivity of the Astro-E HSD will be higher by more than one order of magnitude than that of any previous instrument between 10 keV and several 100 keV. The electronic system is designed to handle many independent data channels from the HXD within the limitation of size and power consumption required in Astro-E. In this paper, we will present the design and the preliminary performance of the processing electronic system., 1998年, 3445, 155, 168
• 査読無し, その他, American Astronomical Society, 193rd AAS Meeting, Bulletin of the American Astronomical Society, Astro-E Hard X-ray Detector, 太田 直美; Kamae, T; Fukazawa, Y; Iyomoto, N; Kaneda, H; Kawaguchi, G; Kokubun, M; Kubota, A; Isobe, N; Makishima, K; Matsumoto, Y; Matsuzaki, K; Nakazawa, K; Obayashi, H; Ohnishi, T; Sugiho, M; Tanaka, M; Tashiro, M; Terada, Y; Kataoka, J; Kubo, S; Murakami, T; Ota, N; Ozawa, H; Sugizaki, M; Takahashi, T; Tamura, T; Tanihata, C; Yamaoka, K; Uchiyama, Y; Nomachi, M; Yoshida, A; Ikeda, H; Ohsugi, T; Yoshida, S; Astro-E Hard; X-ray Detector Team, 1998年, 30, 1374
• 査読無し, 英語, HOT UNIVERSE, KLUWER ACADEMIC PUBL, ASCA observations of three gravitational lensing clusters of galaxies; CL0500-24, CL2244-02, and A370, N Ota; K Mitsuda; Y Fukazawa, We determined the X-ray temperatures of three gravitational lensing: clusters, CL0500-24, CL2244-02, and A370, and obtained significant constraints on the surface brightness profile assuming the beta-model and the King model profiles. The mass of the cluster estimated from these X-ray data is by a factor of two to three smaller than the mass estimated from lens models for two of the clusters., 1998年, 188, 319, 320
• 査読無し, 英語, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY IX, SPIE-INT SOC OPTICAL ENGINEERING, The electronic system for the Astro-E Hard X-ray Detector, T Takahashi; M Nomachi; Y Fukazawa; M Tashiro; H Ezawa; M Hamaya; M Horii; N Isobe; N Iyomoto; J Kataoka; T Kamae; G Kawaguchi; H Kubo; S Kubo; A Kubota; M Kokubun; K Makishima; K Matsuzaki; Y Matsumoto; T Mizuno; K Mori; N Morita; T Murakami; K Nakazawa; H Obayashi; Odagi, I; T Onishi; N Ota; H Ozawa; K Sato; K Sato; M Sugiho; M Sugizaki; K Taguchi; T Tamura; Y Tanaka; C Tanihata; Y Terada; Y Uchiyama; K Yamaoka; A Yoshida, The Hard X-ray Detector (HXD) is one of three instruments on the fifth Japanese X-ray astronomy satellite. Astro-E, scheduled for launch in 2000. The sensitivity of the Astro-E HSD will be higher by more than one order of magnitude than that of any previous instrument between 10 keV and several 100 keV. The electronic system is designed to handle many independent data channels from the HXD within the limitation of size and power consumption required in Astro-E. In this paper, we will present the design and the preliminary performance of the processing electronic system., 1998年, 3445, 155, 168
• 査読無し, その他, American Astronomical Society, 193rd AAS Meeting, Bulletin of the American Astronomical Society, Astro-E Hard X-ray Detector, OTA Naomi; Kamae, T; Fukazawa, Y; Iyomoto, N; Kaneda, H; Kawaguchi, G; Kokubun, M; Kubota, A; Isobe, N; Makishima, K; Matsumoto, Y; Matsuzaki, K; Nakazawa, K; Obayashi, H; Ohnishi, T; Sugiho, M; Tanaka, M; Tashiro, M; Terada, Y; Kataoka, J; Kubo, S; Murakami, T; Ota, N; Ozawa, H; Sugizaki, M; Takahashi, T; Tamura, T; Tanihata, C; Yamaoka, K; Uchiyama, Y; Nomachi, M; Yoshida, A; Ikeda, H; Ohsugi, T; Yoshida, S; Astro-E Hard; X-ray Detector Team, 1998年, 30, 1374
• 査読無し, 英語, HOT UNIVERSE, KLUWER ACADEMIC PUBL, ASCA observations of three gravitational lensing clusters of galaxies; CL0500-24, CL2244-02, and A370, N Ota; K Mitsuda; Y Fukazawa, We determined the X-ray temperatures of three gravitational lensing: clusters, CL0500-24, CL2244-02, and A370, and obtained significant constraints on the surface brightness profile assuming the beta-model and the King model profiles. The mass of the cluster estimated from these X-ray data is by a factor of two to three smaller than the mass estimated from lens models for two of the clusters., 1998年, 188, 319, 320
• その他, 日本天文学会年会講演予稿集, 「ひとみ」によるペルセウス座銀河団のガス速度測定:(1)速度構造, 一戸悠人; 飯塚亮; 井上翔太; 上田周太朗; 太田直美; 北山哲; 佐藤浩介; 田中桂悟; 田村隆幸; 辻本匡弘; 藤本龍一; 前田良知, 2017年, 2017
• その他, 日本天文学会年会講演予稿集, 「ひとみ」によるペルセウス座銀河団のガス速度測定:(2)輝線の非ガウス性とイオン温度への制限, 上田周太朗; 飯塚亮; 一戸悠人; 井上翔太; 太田直美; 北山哲; 佐藤浩介; 田中桂悟; 田村隆幸; 辻本匡弘; 藤本龍一; 前田良知, 2017年, 2017
• その他, 日本天文学会年会講演予稿集, 「ひとみ」によるペルセウス座銀河団の高温ガスの速度場の測定, 上田周太朗; 一戸悠人; 藤本龍一; 井上翔太; KILBOURNE Caroline; 北山哲; MARKEVITCH Maxim; MCNAMARA Brian; 太田直美; PORTER Scott; 田村隆幸; 田中桂悟; WERNER Norbert, 2017年, 2017
• その他, 日本天文学会年会講演予稿集, 重力レンズ多重像を持つBALクェーサーH1413+117のX線観測, 大島泰; 満田和久; 太田直美; 二元和朗; 服部誠; 池辺靖; KNEIB J. P.; MIRALLES J. M., 2001年, 2001
• その他, 日本天文学会年会講演予稿集, 多重像をもつブレーザーPKS1830-211のX線観測, 大島泰; 満田和久; 太田直美; 関本裕太郎; 服部誠, 2000年, 2000
• その他, 日本天文学会年会講演予稿集, 重力レンズ銀河団のALMAデータを用いたCO光度関数の制限, 山口裕貴; 河野孝太郎; 田村陽一; 大栗真宗; 泉拓磨; 北山哲; 江澤元; 大島泰; 松尾宏; 太田直美, 2017年, 2017
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 26pGJ-14 ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(IV)(26pGJ X線(ASTRO-Hなど),宇宙線・宇宙物理領域), 満田 和久; 山崎 典子; 竹井 洋; 辻本 匡弘; 小川 美奈; 杉田 寛之; 佐藤 洋一; 篠崎 慶亮; 岡本 篤; 大橋 隆哉; 石崎 欣尚; 江副 祐一郎; 藤本 龍一; 星野 晶夫; 田代 信; 寺田 幸功; 北本 俊二; 村上 弘志; 玉川 徹; 佐藤 浩介; 太田 直美; 村上 正秀; Kelley R.L.; Kilbourne C.A.; Porter F.S.; Snedermann G.A.; Boyce K.R.; DiPirro M.J.; Shirron P.J.; Gentreau K.C.; Brown G.V.; McCammon D.; Szymkowiak A.; Herder J.-W. den; Vries C. de; Costantini E.; Paltani S.; Pohl M., 2012年03月05日, 67, 1, 141, 141
• その他, 日本天文学会年会講演予稿集, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 II, 佐藤浩介; 大橋隆哉; 石崎欣尚; 江副祐一郎; 山田真也; 山崎典子; 満田和久; 石田学; 前田良知; 田原譲; 三石郁之; 藤本龍一; 鶴剛; 太田直美; 大里健; 中島真也, 2018年, 2018
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 23aWJ-9 ASTRO-E衛星硬X線検出器PIN型シリコンダイオードのエネルギー応答の測定, 杉保 昌彦; 釜江 常好; 牧島 一夫; 田代 信; 深沢 泰司; 高橋 忠幸; 村上 敏夫; 太田 直美; 米徳 大輔; 渡辺 伸, 2000年09月10日, 55, 2, 67, 67
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 24pXK-11 Astro-E2衛星搭載精密X線分光装置XRSの現状(X線衛星装置開発,宇宙線・宇宙物理), 藤本 龍一; 古庄 多恵; 石崎 欣尚; 竹井 洋; 森田 うめ代; 山本 幹生; 太田 直美; 山崎 典子; 満田 和久; Boyce K. R.; Brown G.; Cottam J.; Kelley R. L.; Kilbourne C. A.; McCammon D.; Porter S.; XRS team, 2005年03月04日, 60, 1, 90, 90
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 24pXA-1 X線診断で探る銀河団プラズマの熱的および力学的な進化(プラズマ宇宙物理(原子過程・観測・計測1),領域2(プラズマ基礎・プラズマ科学・核融合プラズマ・プラズマ宇宙物理)), 牧島 一夫; 国分 紀秀; 高橋 勲; 川原田 円; 北口 貴雄; 大橋 隆哉; 深沢 泰司; 松下 恭子; 田村 隆幸; 中澤 知洋; 太田 直美; 池辺 靖, 2005年03月04日, 60, 1, 197, 197
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 25pSD-8 ASTRO-E衛星搭載PIN半導体検出器の開発とフライト品の性能, 太田 直美; 村上 敏夫; 高橋 忠幸; 田村 隆幸; 牧島 一夫; 釜江 常好; 田代 信; 深沢 泰司; HXDチーム, 1999年09月13日, 54, 2, 82, 82
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 28a-YK-10 3CR184を含む遠方大銀河団のX線観測, 三原 建弘; 野上 杏子; 服部 誠; 満田 和久; 太田 直美, 1999年03月15日, 54, 1, 76, 76
• 日本語, 日本物理学会講演概要集, 一般社団法人日本物理学会, 2a-J-2 ASTRO-E衛星搭載PIN型半導体検出器の表面処理と長期的性能, 太田 直美; 村上 敏夫; 小澤 秀樹; 久保 信; 杉崎 睦; 高橋 忠幸; 満田 和久; 牧島 一夫; 釜江 常好; 田代 信; 深沢 泰司, 1998年03月10日, 53, 1, 79, 79
• 日本語, 天文月報, 日本天文学会, X線による銀河団の構造と進化の系統的な研究 - 銀河団規模での二重構造の発見 -, 太田 直美, 2001年08月20日, 94, 9, 414, 422

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• その他, 日本天文学会年会講演予稿集, X線分光撮像衛星XRISMの科学運用に向けての模擬試験, 林克洋; 田代信; 田代信; 寺田幸功; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 米山友景; 吉田鉄生; BALUTA Chris; 海老沢研; 江口智士; 深澤泰司; 橋口葵; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内田悠介; 内山秀樹; 山田智史; 山内茂雄, 2023年, 2023
• その他, 日本天文学会年会講演予稿集, X線分光撮像衛星XRISMの観測データ処理ツールの開発状況, 山田智史; 田代信; 田代信; 寺田幸功; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 林克洋; 米山友景; 吉田鉄生; BALUTA Chris; 海老沢研; 江口智士; 深澤泰司; 橋口葵; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内田悠介; 内山秀樹; 山内茂雄, 2023年, 2023
• その他, 日本天文学会年会講演予稿集, X線分光撮像衛星XRISMの科学運用準備の現状(2), 米山友景; 田代信; 田代信; 寺田幸功; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 林克洋; 吉田鉄生; BALUTA Chris; 海老沢研; 江口智士; 深澤泰司; 橋口葵; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内田悠介; 内山秀樹; 山田智史; 山内茂雄, 2023年, 2023
• その他, 日本天文学会年会講演予稿集, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画FORCEの現状(15), 森浩二; 武田彩希; 村上弘志; 寺田幸功; 久保田あや; 山田智史; 馬場彩; 小高裕和; 谷津陽一; 小林翔悟; 幸村孝由; 内山泰伸; 佐藤寿紀; 北山哲; 高橋忠幸; 石田学; 渡辺伸; 山口弘悦; 藤田裕; 中嶋大; 萩野浩一; 中澤知洋; 古澤彰浩; 鶴剛; 上田佳宏; 内田裕之; 榎戸輝揚; 水本岬希; 田中孝明; 鈴木寛大; 松本浩典; 野田博文; 常深博; 伊藤真之; 信川正順; 信川久実子; 太田直美; 粟木久光; 寺島雄一; 志達めぐみ; 深沢泰司; 水野恒史; 高橋弘充; 谷本敦; 赤松弘規; HORNSCHEMEIER Ann.E; OKAJIMA Takashi; ZHANG W.William; VENTERS Tonia; YUKITA Mihoko, 2023年, 2023
• その他, 日本物理学会講演概要集(CD-ROM), X線分光撮像衛星XRISMの科学運用への準備状況, 内田悠介; 田代信; 田代信; 寺田幸功; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 米山友景; 吉田鉄生; BALUTA Chris; 海老沢研; 江口智士; 深澤泰司; 橋口葵; 林克洋; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内山秀樹; 山田智史; 山内茂雄, 2023年, 78, 1
• その他, 日本物理学会講演概要集(CD-ROM), 広帯域X線の高感度観測衛星FORCE:2023年春におけるミッション提案の現状, 中澤知洋; 森浩二; 村上弘志; 赤松弘規; 久保田あや; 幸村孝由; 小林翔悟; 高橋忠幸; 馬場彩; 萩野浩一; 寺田幸功; 内山泰伸; 佐藤寿紀; 石村康生; 北山哲; 谷津陽一; 藤田裕; 石田学; 渡辺伸; 山口弘悦; 中嶋大; 古澤彰浩; 信川正順; 太田直美; 鶴剛; 上田佳宏; 榎戸輝揚; 内田裕之; 水本岬希; 信川久実子; 松本浩典; 小高裕和; 野田博文; 常深博; 田中孝明; 鈴木寛大; 伊藤真之; 粟木久光; 寺島雄一; 志達めぐみ; 深沢泰司; 水野恒史; 高橋弘充; 武田彩希; 谷本敦; HORNSCHEMEIER A.E.; 岡島崇; ZHANG W.W., 2023年, 78, 1
• その他, 日本天文学会年会講演予稿集, X線分光撮像衛星XRISMの科学運用準備の現状(3), 林克洋; 田代信; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 星野晶夫; 吉田鉄生; 小川翔司; 金丸善朗; BALUTA Chris; 海老沢研; 江口智士; 小高裕和; 勝田哲; 北口貴雄; 新居田祐基; 太田直美; 阪本菜月; 志達めぐみ; 塩入匠; 白木天音; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内田悠介; 内山秀樹; 山田智史; 山内茂雄; 米山友景, 2023年, 2023
• その他, 日本物理学会講演概要集(CD-ROM), 広帯域X線の高感度観測衛星FORCE:2022年秋におけるミッション提案の現状, 中澤知洋; 森浩二; 村上弘志; 久保田あや; 小林翔悟; 幸村孝由; 高橋忠幸; 馬場彩; 小高裕和; 谷本敦; 寺田幸功; 榎戸輝揚; 内山泰伸; 佐藤寿紀; 石村康生; 北山哲; 谷津陽一; 藤田裕; 石田学; 渡辺伸; 山口弘悦; 中嶋大; 萩野浩一; 古澤彰浩; 信川正順; 太田直美; 鶴剛; 上田佳宏; 内田裕之; 水本岬希; 信川久実子; 松本浩典; 野田博文; 常深博; 田中孝明; 鈴木寛大; 伊藤真之; 粟木久光; 寺島雄一; 志達めぐみ; 深沢泰司; 水野恒史; 高橋弘充; 武田彩希; 赤松弘規; HORNSCHEMEIER A.E.; 岡島崇; ZHANG W.W., 2022年, 77, 2

講演・口頭発表等

• 太田直美, 国内, 第11回 山田研究会「宇宙における降着現象 ～活動性・多様性の源～」, 銀河団のX線観測: 現状とXRISMへの展望, 口頭発表（招待・特別）, 2023年06月03日, 2023年06月05日, 日本語
• Aoi Hashiguchi, 国際, Tracing the SMBH growth: outlook beyond the HSC-SSP, and future collaborations, AGN fraction distribution in the galaxy clusters selected with the Subaru HSC, ポスター発表, 2022年11月30日, 2022年12月02日, 英語
• 森浩二;武田彩希;村上弘志;寺田幸功;久保田あや;榎戸輝揚;馬場彩;小高裕和;谷津陽一;小林翔悟;幸村孝由;萩野浩一;内山泰伸;佐藤寿紀;北山哲;高橋忠幸;高橋忠幸;石田学;渡辺伸;山口弘悦;藤田裕;中嶋大;中澤知洋;古澤彰浩;鶴剛;上田佳宏;内田裕之;田中孝明;鈴木寛大;松本浩典;野田博文;常深博;伊藤真之;信川正順;信川久実子;太田直美;粟木久光;寺島雄一;深沢泰司;水野恒史;高橋弘充;大野雅, 国内, 日本天文学会2021年秋期年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画FORCEの現状(12), 口頭発表（一般）, 2021年09月13日, 2021年09月15日, 日本語
• 森浩二;武田彩希;村上弘志;寺田幸功;久保田あや;榎戸輝揚;馬場彩;小高裕和;谷本敦;谷津陽一;小林翔悟;幸村孝由;萩野浩一;内山泰伸;藤寿紀;北山哲;高橋忠幸;石田学;渡辺伸;山口弘悦 藤田;裕;中嶋大;中澤知洋;古澤彰浩;鶴剛;上田佳宏;内田裕之;水本岬希;田中孝明;鈴木寛大;松本浩典;野田博文;常深博;伊藤真之;信川正順;川久実子;太田直美;粟木久光;寺島雄一;志達めぐみ;深沢泰司;水野恒史, 国内, 日本天文学会2022年春季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画FORCEの現状(13), 口頭発表（一般）, 2022年03月02日, 2202年03月05日, 日本語
• 佐藤浩介;山崎典子;石田学;前田良知;満田和久;三石郁之;田原譲;石崎欣尚;江副祐一郎;藤田裕;藤本龍一;鶴剛;大里健;太田直美;永井大輔;吉川耕司;河合誠之;松下恭子;山田真也;一戸悠人;内田悠介;中島裕貴, 国内, 日本天文学会2021年秋季年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 VIII, 口頭発表（一般）, 2021年09月13日, 2021年09月15日, 日本語
• 佐藤浩介;山崎典子;石田学;前田良知;満田和久;三石郁之;田原譲;石崎欣尚;江副祐一郎;藤田裕;藤本龍一;鶴剛;大里健;太田直美;永井大輔;吉川耕司;河合誠之;松下恭子;山田真也;一戸悠人;内田悠介;中島裕貴, 国内, 日本天文学会2022年春季年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 IX, 口頭発表（一般）, 2022年03月02日, 2022年03月05日, 日本語
• 高橋弘充;田代信;寺田幸功;信川正順;水野恒史;宇野伸一郎;久保田あや;中澤知洋;渡辺伸;飯塚亮;佐藤理江;林克洋;米山友景;Chris Baluta;海老沢研;江口智士;深澤泰司;加藤颯;勝田哲;北口貴雄;小高裕和;大野雅功;太田直美;阪間美南;佐藤諒平;志達めぐみ;菅原泰晴;丹波翼;谷本敦;寺島雄一;坪井陽子;内田和海;内田悠介;内山秀樹;山内, 国内, 日本天文学会2022年春季年会, Ｘ線分光撮像衛星XRISMの観測データ処理とその準備状況, 口頭発表（一般）, 2022年03月02日, 2022年03月05日, 日本語
• 林克洋;田代信;寺田幸功;高橋弘充;信川正順;水野恒史;宇野伸一郎;久保田あや;中澤知洋;渡辺伸;飯塚亮;佐藤理江;米山友景;Chris Baluta;海老沢研;江口智士;深澤泰司;加藤颯;勝田哲;北口貴雄;小高裕和;大野雅功;太田直美;阪間美南;佐藤諒平;志達めぐみ;菅原泰晴;丹波翼;谷本敦;寺島雄一;坪井陽子;内田和海;内田悠介;内山秀樹;山内茂雄, 国内, 日本天文学会2022年春季年会, X線分光撮像衛星XRISMの科学運用準備の現状, 口頭発表（一般）, 2022年03月02日, 2022年03月05日
• 柴田実桜;太田直美;北山哲;小松英一郎;赤堀卓也;永吉賢一郎;上田周太朗, 国内, 日本天文学会2022年春季年会, NuSTAR衛星によるRX J1347.5–1145銀河団の硬X線観測, 口頭発表（一般）, 2022年03月02日, 2022年03月05日, 日本語
• 橋口葵, 国内, 日本天文学会2022年春季年会, すばる望遠鏡を用いた銀河団中のAGN fraction分布の調査, 口頭発表（一般）, 2022年03月02日, 2022年03月05日, 日本語
• 鳥羽儀樹;守屋碧;太田直美;山田智史;城知磨;松林和也;橋口葵;柴田実桜;美里らな;上田佳宏, 国内, 日本天文学会2021年秋期年会, せいめい望遠鏡KOOLS-IFU可視面分光観測で探るNGC7674のAGN活動, 口頭発表（一般）, 2021年09月13日, 2021年09月15日, 日本語
• 田中桂悟; 藤本龍一; 岡部信広; 三石郁之; 志村拓馬; 作田皓基; 赤松弘規; 太田直美; 美里らな; 他 HSC; 銀河団コラボレーション, 国内, 日本天文学会2021年春期年会, HSC-SSP領域内の可視光で選択された衝突銀河団のX線フォローアップ計画 (3), 2021年03月16日, 2021年03月18日, 2021年03月19日, 日本語
• 作田皓基; 山口友洋; 三石郁之; 浜名崇; 宮崎聡; 大栗真宗; 太田直美; 岡部信広; 赤松弘規; 上田周太朗; ASIAA; 田中桂悟; 他 HSC; 銀河団コラボレーション, 国内, 日本天文学会2021年春期年会, HSC-SSPサーベイ領域Weak Lensing銀河団のX線フォローアップ計画 (7), 2021年03月18日, 2021年03月16日, 2021年03月19日, 日本語
• 佐藤浩介; 大橋隆哉; 石崎欣尚; 江副祐一郎; 藤田裕; 山崎典子; 石田学; 前田良知; ISAS/JAXA; 満田和久; 中島裕貴; 三石郁之; 田原譲; 藤本龍一; 金沢大; 鶴剛; 太田直美; 大里健 (IA; 永井大輔; 吉川耕司; 河合誠之; 松下恭子; 山田真也; 一戸悠人; 内田悠介, 国内, 日本天文学会2021年春期年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 VII, 2021年03月17日, 2021年03月16日, 2021年03月19日, 日本語
• 佐藤 浩介; 大橋 隆哉; 石崎 欣尚; 江副 祐一郎; 山田 真也; 山崎 典子; 満田 和久; 石田 学; 前田 良知; 中島 裕貴; 三石 郁之; 田原 譲; 藤本龍一; 鶴 剛; 太田 直美; 河合 誠之; 松下 恭子; 藤田 裕; 永井 大輔; 吉川 耕司; 大里 健; 一戸 悠人; 内田 悠介, 国内, 第21回宇宙科学シンポジウム, ダークバリオン探査衛星: Super DIOS, 2021年01月06日, 2021年01月06日, 2021年01月07日, 日本語
• Naomi Ota, 国際, NECO workshop: Probing the Extragalactic Universe with High Energy and Very High Energy Sources, Clusters of galaxies seen in X-rays: current status and prospects, 口頭発表（招待・特別）, 2020年12月09日, 2020年12月09日, 2020年12月11日, 英語
• 美里らな; 太田直美; 鳥羽儀樹; 児玉忠恭; 山本直明; 岡部信広; 三石郁之; 他 HSC; 銀河団コラボレーション, 国内, 日本天文学会2020年秋期年会, すばる望遠鏡で見つかった青い銀河団のX線ガスの性質, 口頭発表（一般）, 2020年09月10日, 2020年09月08日, 2020年09月10日, 日本語
• 田中桂悟; 藤本龍一; 岡部信広; 三石郁之; 志村拓馬; 作田皓基; 赤松弘規(SRON; 太田直美; 美里らな; 他 HSC; 銀河団コラボレーション, 国内, 日本天文学会2020年秋期年会, HSC-SSP領域内の可視光で選択された衝突銀河団のX線フォローアップ計画 (2), 2020年09月10日, 2020年09月08日, 2020年09月10日, 日本語
• 作田皓基; 志村拓馬; 三石郁之; 浜名崇; 宮崎聡; 大栗真宗; 太田直美; 岡部信広; 赤松弘規; 上田周太朗; ASIAA; 田中桂悟; 他 HSC; 銀河団コラボレーション, 国内, 日本天文学会2020年秋期年会, HSC-SSP サーベイ領域 Weak Lensing 銀河団の X 線フォローアップ計画 (6), 2020年09月10日, 2020年09月08日, 2020年09月10日, 日本語
• 佐藤浩介; 大橋隆哉; 石崎欣尚; 江副祐一郎; 藤田裕; 山崎典子; 石田学; 前田良知; ISAS/JAXA; 満田和久; 三石郁之; 田原譲; 藤本龍一; 鶴剛; 太田直美; 大里健 (IA; 永井大輔; 吉川耕司; 河合誠之; 松下恭子; 山田真也; 一戸悠人; 内田悠介, 国内, 日本天文学会2020年秋期年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 VI, 2020年09月08日, 2020年09月08日, 2020年09月10日, 日本語
• 松本浩典; 山崎典子; ISAS; JAXA; 満田和久; 篠崎慶亮; 前田良知(ISAS; JAXA; 粟木久光; 坪井陽子; 江副祐一郎; 山口弘悦; ISAS; JAXA; 佐藤浩介; 中嶋大; 深沢泰司; 大橋隆哉; 上田佳宏; 寺島雄一; 太田直美; 馬場彩; 海老沢研; ISAS; JAXA; 寺田幸功; 鶴剛; 常深博, 国内, 日本天文学会2020年秋期年会, X 線天文衛星Athena計画の現状, 2020年09月08日, 2020年09月08日, 2020年09月10日, 日本語
• 佐藤浩介; 大橋隆哉; 石崎欣尚; 江副祐一郎; 山田真也; 山崎典子; 満田和久; 石田学; 前田良知; 田原譲; 三石郁之; 藤本龍一; 鶴剛; 太田直美; 大里健; 中島真也, 日本天文学会年会講演予稿集, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 II, 2018年08月20日, 2018年08月20日, 2018年08月20日, 日本語

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• Preparing the science of galaxy clusters & WHIM with Athena, XARM status and some prospects, 2018年, その他
• 第18回宇宙科学シンポジウム, X線衛星代替機における科学運用の計画概要, 2018年, その他
• 第18回宇宙科学シンポジウム, X線天文衛星 Athena の現状, 2018年, その他
• 日本天文学会2018年春季年会, 近傍銀河団 A2319 内に存在するサブハローのガス質量比の測定, 2018年, その他
• 日本天文学会2018年春季年会, X線/可視光を用いた低表面輝度銀河団の力学状態の研究, 2018年, その他
• 日本天文学会2018年春季年会, HSC による弱重力レンズ効果を利用した銀河団探査, 2018年, その他
• 日本天文学会2018年春季年会, XMM-Newton 衛星による 5 つの高赤方偏移 HSC 銀河団の観測, 2018年, その他
• 日本天文学会2018年春季年会, HSC-SSPサーベイ領域 Weak Lensing 銀河団のＸ線フォローアップ計画 (2), 2018年, その他
• 日本天文学会2018年春季年会, X線衛星代替機 XARM における科学運用計画, 2018年, その他
• 日本天文学会2018年春季年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討II, 2018年, その他
• 日本天文学会2018年春季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する小型衛星計画 FORCE の現状 (6), 2018年, その他
• Preparing the science of galaxy clusters & WHIM with Athena, XARM status and some prospects, 2018年, その他
• 第17回宇宙科学シンポジウム, 「ひとみ」搭載軟X線帯観測装置の軌道上性能, 2017年, その他
• 日本天文学会2017年春季年会, 「すざく」で観測した近傍銀河団・銀河群のエントロピー分布, 2017年, その他
• 日本天文学会2017年春季年会, 「すざく」衛星による Abell2163 銀河団外縁部の詳細な解析, 2017年, その他
• 日本天文学会2017年春季年会, 「ひとみ」によるペルセウス座銀河団のガス速度測定: (2) 輝線の非ガウス性 とイオン温度への制限, 2017年, その他
• 日本天文学会2017年春季年会, 「ひとみ」によるペルセウス座銀河団のガス速度測定: (1) 速度構造, 2017年, その他
• 日本天文学会2017年春季年会, 「ひとみ」SXS 精密分光による銀河団プラズマの新X線スペクトル構造探査, 2017年, その他
• 日本天文学会2017年春季年会, ALMA によるスニヤエフ・ゼルドビッチ効果の初観測, 2017年, その他
• 日本天文学会2017年春季年会, すざく衛星を用いた A222/223 ブリッジ領域におけるミッシングバリオン探査, 2017年, その他
• 日本物理学会 第72回年次大会, 1-80 keV の広帯域X線を高感度で撮像分光する次世代の小型科学衛星計画 FORCE：2017年のステータス, 2017年, その他
• The X-ray Universe 2017, Constraints on new spectral features and atomic modeling from the Hitomi spectrum of the Perseus cluster, 2017年, その他
• The X-ray Universe 2017, Gas motions in the Perseus galaxy cluster observed with Hitomi, 2017年, その他
• Whereabouts and Physics of the Roaming Baryons in the Universe, Suzaku study of the WHIM and future prospects, 2017年, その他
• Early Stages of Galaxy Cluster Formation, X-ray Follow-up Survey in the Hyper Suprime-Cam Subaru Strategic Program Field, 2017年, その他
• 日本天文学会2017年秋季年会, 「ひとみ」によるペルセウス座銀河団の高温ガスの速度場の測定, 2017年, その他
• 日本天文学会2017年秋季年会, 多波長観測から迫る銀河団RXC J1053.7+5453の衝突過程と粒子加速, 2017年, その他
• 日本天文学会2017年秋季年会, HSC-SSP サーベイ領域にある可視銀河団のX線フォローアップ計画, 2017年, その他
• 日本天文学会2017年秋季年会, HSC-SSPサーベイ領域Weak Lensing銀河団のX線フォローアップ計画, 2017年, その他
• 日本天文学会2017年秋季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する小型衛星計画 FORCE の 現状 (5), 2017年, その他
• 日本天文学会2017年秋季年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討, 2017年, その他
• 日本天文学会2017年秋季年会, X線天文衛星 Athena計画, 2017年, その他
• The X-ray Universe 2017, Constraints on new spectral features and atomic modeling from the Hitomi spectrum of the Perseus cluster, 2017年, その他
• The X-ray Universe 2017, Gas motions in the Perseus galaxy cluster observed with Hitomi, 2017年, その他
• Whereabouts and Physics of the Roaming Baryons in the Universe, Suzaku study of the WHIM and future prospects, 2017年, その他
• Early Stages of Galaxy Cluster Formation, X-ray Follow-up Survey in the Hyper Suprime-Cam Subaru Strategic Program Field, 2017年, その他
• 第16回宇宙科学シンポジウム, ASTRO-Hの目指すサイエンス, 2016年, その他
• 第16回宇宙科学シンポジウム, ASTRO-H 衛星搭載 軟X線分光システム SXS, 2016年, その他
• 日本天文学会2016年春季年会, すざく衛星による RXC J1053.7+5453 の電波レリック周辺領域の解析, 2016年, その他
• 日本天文学会2016年春季年会, すざく衛星による Abell 2744 銀河団周辺のミッシングバリオン探査, 2016年, その他
• 日本天文学会2016年春季年会, ダークバリオン探査ミッションDIOS開発の進展状況, 2016年, その他
• 日本天文学会2016年春季年会, ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XV, 2016年, その他
• 日本物理学会 第71回年次大会, ASTRO-H搭載 精密軟X線分光装置SXSの現状, 2016年, その他
• 日本天文学会2016年秋季年会, すざく衛星による銀河団 RXC J1053.7+5453 の温度測定, 2016年, その他
• 日本天文学会2016年秋季年会, ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XVI, 2016年, その他
• 第15回宇宙科学シンポジウム, すざく衛星による衝突銀河団A2255, A2744の温度構造の研究, 2015年, その他
• 第15回宇宙科学シンポジウム, 「すざく」衛星による電波レリック領域のX線観測: 銀河団における粒子加速機構の理解に向けて, 2015年, その他
• 第15回宇宙科学シンポジウム, 「すざく」で探す銀河団外縁部のサブハロー/ガス塊, 2015年, その他
• 第15回宇宙科学シンポジウム, ASTRO-Hの目指すサイエンス, 2015年, その他
• 第15回宇宙科学シンポジウム, ASTRO-H衛星搭載 SXS-XCS検出器, 2015年, その他
• American Astronomical Society, AAS Meeting, New Frontiers in Galaxy Clusters with ASTRO-H, 2015年, その他
• 日本天文学会2015年春季年会, ASTRO-H搭載精密軟X線分光装置SXSの開発の現状 XIII, 2015年, その他
• Astroparticle View of Galaxy Clusters, Prospects of Cluster Observations with ASTRO-H, 2015年, その他
• IAU General Assembly, Meeting #29, New Frontiers in Galaxy Clusters with ASTRO-H, 2015年, その他
• Exploring the Hot and Energetic Universe: The first Scientific Conference dedicated to the Athena X-ray Observatory, Evolution of Groups and Clusters of Galaxies with Athena, 2015年, その他
• 日本天文学会2015年秋季年会, 「すざく」衛星によるAbell2163銀河団による銀河団外縁部までの観測, 2015年, その他
• 日本天文学会2015年秋季年会, ダークバリオン探査ミッションDIOS開発の進展状況, 2015年, その他
• 日本天文学会2015年秋季年会, ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XIV, 2015年, その他
• American Astronomical Society, AAS Meeting, New Frontiers in Galaxy Clusters with ASTRO-H, 2015年, その他
• Astroparticle View of Galaxy Clusters, Prospects of Cluster Observations with ASTRO-H, 2015年, その他
• IAU General Assembly, Meeting #29, New Frontiers in Galaxy Clusters with ASTRO-H, 2015年, その他
• Exploring the Hot and Energetic Universe: The first Scientific Conference dedicated to the Athena X-ray Observatory, Evolution of Groups and Clusters of Galaxies with Athena, 2015年, その他
• 第14回宇宙科学シンポジウム, ASTRO-H の目指すサイエンス, 2014年, その他
• 第14回宇宙科学シンポジウム, ASTRO-H 衛星搭載 SXS-XCS 検出器, 2014年, その他
• 第14回宇宙科学シンポジウム, すざく衛星による低表面輝度銀河団A1631のエントロピー測定, 2014年, その他
• Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Exploring gas properties along filaments of the Pandora’s cluster with Suzaku, 2014年, その他
• Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for gas bulk motions in eight nearby clusters with Suzaku, 2014年, その他
• Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for very hot/non-thermal emission and gas motions in clusters, 2014年, その他
• 日本天文学会2014年春季年会, ASTRO-H搭載精密軟X線分光装置SXSの開発の現状XI, 2014年, その他
• 日本物理学会 第69回年次大会, ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 (VI), 2014年, その他
• 日本天文学会2014年秋季年会, すざく衛星による低表面輝度銀河団 A1631 のエントロピー分布の研究, 2014年, その他
• 日本天文学会2014年秋季年会, 銀河団外縁部のエントロピー異常の原因の検証, 2014年, その他
• 日本天文学会2014年秋季年会, ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XII, 2014年, その他
• Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Exploring gas properties along filaments of the Pandora’s cluster with Suzaku, 2014年, その他
• Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for gas bulk motions in eight nearby clusters with Suzaku, 2014年, その他
• Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, Search for very hot/non-thermal emission and gas motions in clusters, 2014年, その他
• 第13回宇宙科学シンポジウム, ASTRO-H の目指すサイエンス, 2013年, その他
• 第13回宇宙科学シンポジウム, ASTRO-H 衛星搭載 SXS-XCS 検出器, 2013年, その他
• 第13回宇宙科学シンポジウム, すざく衛星による近傍銀河団のガスバルク運動の測定, 2013年, その他
• 第13回宇宙科学シンポジウム, すざく衛星を用いた遠方の衝突銀河団A2744のフィラメント構造の研究, 2013年, その他
• 第13回宇宙科学シンポジウム, 「すざく」が捉えた銀河団ビリアル半径までの高温ガスの構造, 2013年, その他
• The 8th ASTRO-H Science Meeting, Galaxy Clusters: Mapping Non-Thermal Pressure & Measuring Mass, 2013年, その他
• The mass profiles of galaxy clusters from the core to the outskirts: the need for a multi-wavelength approach, Density profile of cool core of galaxy clusters, 2013年, その他
• 日本天文学会2013年春季年会, XMM-Newton衛星を用いた低表面輝度銀河団A1631のエントロピー測定, 2013年, その他
• 日本天文学会2013年春季年会, すざく衛星による遠方の衝突銀河団A2744のフィラメント領域の観測, 2013年, その他
• 日本天文学会2013年春季年会, すざく衛星による近傍銀河団のガスバルク運動の探査, 2013年, その他
• 日本天文学会2013年春季年会, ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(IX), 2013年, その他
• The 8th IACHEC meeting, Status of ASTRO-H, 2013年, その他
• 日本物理学会 第68回年次大会, ASTRO-H搭載 精密軟X線分光装置SXSの開発の現状(V), 2013年, その他
• 日本物理学会 第68回年次大会, ASTRO-H搭載 精密軟X線分光装置SXS 飛翔体モデルアレイの地上較正試験, 2013年, その他
• 日本天文学会2013年秋季年会, ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(X), 2013年, その他
• 日本天文学会2013年秋季年会, 超新星残骸G348.5+0.1のX線放射について, 2013年, その他
• The 8th ASTRO-H Science Meeting, Galaxy Clusters: Mapping Non-Thermal Pressure & Measuring Mass, 2013年, その他
• The mass profiles of galaxy clusters from the core to the outskirts: the need for a multi-wavelength approach, Density profile of cool core of galaxy clusters, 2013年, その他
• The 8th IACHEC meeting, Status of ASTRO-H, 2013年, その他
• 第12回宇宙科学シンポジウム, すざく衛星による低表面輝度銀河団A76のエントロピー測定, 2012年, その他
• 第12回宇宙科学シンポジウム, すざく衛星による超新星残骸 G355.6-0.0 の高温プラズマの観測, 2012年, その他
• 第12回宇宙科学シンポジウム, ASTRO-H の目指すサイエンス 1, 2012年, その他
• 第12回宇宙科学シンポジウム, ASTRO-H の目指すサイエンス ２, 2012年, その他
• 第12回宇宙科学シンポジウム, ASTRO-H 衛星搭載 SXS-XCS 検出器, 2012年, その他
• 第12回宇宙科学シンポジウム, ASTRO-H 衛星用の科学解析用ソフトウェア・キャリブレーション, 2012年, その他
• 日本天文学会2012年春季年会, ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(VII), 2012年, その他
• 日本天文学会2012年春季年会, すざく衛星を用いたThe Bullet Clusterの硬X線探査, 2012年, その他
• 日本天文学会2012年春季年会, Abell 2199 銀河団のビリアル半径までの温度/エントロピー/質量分布, 2012年, その他
• 日本天文学会2012年春季年会, すざく衛星によるHydra A銀河団のビリアル半径近傍までの観測 1, 2012年, その他
• 日本天文学会2012年春季年会, すざく衛星によるHydra A銀河団のビリアル半径近傍までの観測 2, 2012年, その他
• 日本天文学会2012年春季年会, すざく衛星による低表面輝度銀河団A76のエントロピー測定, 2012年, その他
• 日本天文学会2012年春季年会, ASTRO-Hで診る銀河団の進化に伴う銀河団ガスの加熱と粒子加速, 2012年, その他
• 日本天文学会2012年春季年会, すざく衛星による超新星残骸 G355.6-0.0 の高温プラズマの観測, 2012年, その他
• 第12回高エネルギー宇宙物理連絡会研究会「高エネルギー宇宙物理学の将来計画とサイエンス」, 「すざく」による銀河面上に位置する超新星残骸G355.6－0.0の高温プラズマの観測, 2012年, その他
• Vulcano Workshop 2012: Frontier Objects in Astrophysics and Particle Physics, Impact of Suzaku Measurements on Astroparticle Physics, 2012年, その他
• The 8th ASTRO-H Science Meeting, Cluster large-scale dynamics, 2012年, その他
• Science with eROSITA and ART-XC aboard Spectrum-RG, The ASTRO-H Mission, 2012年, その他
• 日本天文学会2012年秋季年会, ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(VIII), 2012年, その他
• 日本天文学会2012年秋季年会, Abell 2199 銀河団の温度、エントロピー分布の方向依存性と鉄の分布, 2012年, その他
• 日本天文学会2012年秋季年会, 「すざく」衛星によるAbell 478銀河団の外縁部の観測, 2012年, その他
• Vulcano Workshop 2012: Frontier Objects in Astrophysics and Particle Physics, Impact of Suzaku Measurements on Astroparticle Physics, 2012年, その他
• The 8th ASTRO-H Science Meeting, Cluster large-scale dynamics, 2012年, その他
• Science with eROSITA and ART-XC aboard Spectrum-RG, The ASTRO-H Mission, 2012年, その他
• Exploring the X-ray Universe: Suzaku and Beyond, Detection of hard X-ray emission from the hottest Abell galaxy cluster A2163 with Suzaku, 2011年, その他
• 日本天文学会2011年秋季年会, 「すざく」衛星によるAbell 1835銀河団の外縁部の研究, 2011年, その他
• 日本天文学会2011年秋季年会, すざく衛星による中規模銀河団 Hydra--A のビリアル半径までの観測, 2011年, その他
• 日本天文学会2011年秋季年会, ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 (VI), 2011年, その他
• Exploring the X-ray Universe: Suzaku and Beyond, Detection of hard X-ray emission from the hottest Abell galaxy cluster A2163 with Suzaku, 2011年, その他
• N Ota; K Mitsuda; Y Fukazawa, ASTROPHYSICAL JOURNAL, ASCA observations of the lensing clusters CL 0500-24, CL 2244-02, and A370: Mass determinations and comparisons, 1998年03月, 1998年03月, 1998年03月, 英語, IOP PUBLISHING LTD, ASCA observations of three gravitational lensing clusters, CL 0500-24, CL 2244-02, and A370, are presented. The X-ray temperatures of the three clusters are determined, respectively, at 7.2 (5.4-10.9), 6.5 (5.2-8.3), and 6.6 (5.7-7.7) keV (90% error), while the X-ray luminosities are determined to be 1.7, 1.3, and 8.3 x 10(44) ergs s(-1) in the 2-10 keV band. We also obtained significant constraints on the surface brightness profile assuming the beta-model and the King model (i.e., the beta-model with beta = 1) profiles. The mass of the cluster estimated from these X-ray data is smaller by a factor of 2-3 than the mass estimated from lens models for two of the clusters, CL 0500-24 and A370, while the two independent mass estimates are consistent with each other for CL 2244-02. We suspect that the major cause of mass discrepancy of CL 0500-24 and A370 is in the projection effect of substructures of these clusters.
• 松本浩典; 山崎典子; 満田和久; 篠崎慶亮; 深沢泰司; 鶴剛; 常深博; 粟木久光; 海老沢研; 大橋隆哉; 太田直美; 馬場彩; 上田佳宏; 寺島雄一, 日本天文学会年会講演予稿集, X線天文衛星Athena計画, 2017年08月20日, 2017年08月20日, 2017年08月20日, 日本語

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• 佐々木亨; 松下恭子; 佐藤浩介; 横田佳奈; 栗山翼; 菅野祐; 赤松弘規; 藤田裕; 中澤知洋; 岡部信広; 大橋隆哉; 太田直美; 田村隆幸; 滝沢元和, 日本天文学会年会講演予稿集, 「すざく」で観測した近傍銀河団・銀河群のエントロピー分布, 2017年02月28日, 2017年02月28日, 2017年02月28日, 日本語

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• 森浩二; 武田彩希; 村上弘志; 寺田幸功; 久保田あや; 馬場彩; 小高裕和; 谷津陽一; 幸村孝由; 萩野浩一; 小林翔悟; 内山泰伸; 北山哲; 高橋忠幸; カブリ IPMU; 石田学; 渡辺伸; 飯塚亮; 山口弘悦; ISAS; JAXA; 大橋隆哉; 中嶋大; 中澤知洋; 古澤彰浩; 鶴剛; 上田佳宏; 田中孝明; 内田裕之; 松本浩典; 野田博文; 常深博; 伊藤真之; 信川正順; 信川久実子; 太田直美; 粟木久光; 寺島雄一; 深沢泰司; 水野恒史; 高橋弘充; 大野雅功; Hornschemeier, A.E; 岡島崇; Zhang, W.W; Williams, B.J; NASA/GSFC; 他 FORCE WG, 日本天文学会2020年春期年会, 軟Ｘ線から硬Ｘ線の広帯域を高感度で撮像分光する小型衛星計画FORCEの現状 (10), 2020年03月19日, 2020年03月16日, 2020年03月19日, 日本語
• 佐藤浩介; 内田悠介; 大橋隆哉; 石崎欣尚; 江副祐一郎; 山田真也; 山崎典子; 中島裕貴; 満田和久; 石田学; 前田良知; ISAS/JAXA; 三石郁之; 田原譲; 藤本龍一; 鶴剛; 太田直美; 大里健 (IA; 中島真也; 藤田裕; 永井大輔; 吉川耕司; 河合誠之; 松下恭子; 一戸悠人, 日本天文学会2020年春期年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 V, 2020年03月18日, 2020年03月16日, 2020年03月19日, 日本語
• 田中桂悟; 藤本龍一; 岡部信広; 赤松弘規(SRON; 太田直美; 美里らな; 三石郁之; 吉田篤史; 志村拓馬; 他 HSC; 銀河団コラボレーション, 日本天文学会2020年春期年会, HSC-SSP領域内の可視光で選択された衝突銀河団のX線フォローアップ計画, 2020年03月16日, 2020年03月16日, 2020年03月19日, 日本語
• 森浩二; 武田彩希; 村上弘志; 寺田幸功; 久保田あや; 榎戸輝揚; 馬; 場彩; 小高裕和; 谷本敦; 谷津陽一; 小林翔悟; 幸村孝由; 萩野浩一; 内山泰伸; 藤寿紀; 北山哲; 高橋忠幸; 石田学; 渡辺伸; 山口弘悦 藤田; 裕; 中嶋大; 中澤知洋; 古澤彰浩; 鶴剛; 上田佳宏; 内田裕之; 水本岬希; 田中孝明; 鈴木寛大; 松本浩典; 野田博文; 常深博; 伊藤真之; 信川正順; 川久実子; 太田直美; 粟木久光; 寺島雄一; 志達めぐみ; 深沢泰司; 水野恒史; 高橋弘充; 大野雅功; 赤松弘; Hornschemeier,A.E; 岡島崇; Zhang,W.W; Venters,T; Yukita; M; 他 FORCE WG, 日本天文学会2022年春期年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画FORCEの現状(13), 2022年03月05日, 2022年03月02日, 2022年03月05日, 日本語
• 佐藤浩介; 山崎典子; 石田学; 前田良知; 満田和久; 三石郁之; 田原譲; 石崎欣尚; 江副祐一郎; 藤田裕; 藤本龍一; 鶴剛; 大里健; 太田直美; 永井大輔; 吉川耕司; 河合誠之; 松下恭子; 山田真也; 一戸悠人; 内田悠介; 中島裕貴, 日本天文学会2022年春期年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 IX, 2022年03月05日, 2022年03月02日, 2022年03月05日, 日本語
• 寺田幸功; 高橋弘充; 飯塚亮; 林克洋; 志達めぐみ; 加藤颯; 佐藤諒平; 他 XRISM; Mission Operation Preparation Team; 小湊隆, 日本天文学会2022年春期年会, Ｘ線分光撮像衛星XRISM時刻システムの地上評価検証, 2022年03月05日, 2022年03月02日, 2022年03月05日, 日本語
• 高橋弘充; 田代信; 寺田幸功; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 林克洋; 米山友景; Chris Baluta; 海老沢研; 江口智士; 深澤泰司; 加藤颯; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 佐藤諒平; 志達めぐみ; 菅原泰晴; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内田悠介; 内山秀樹; 山内, 日本天文学会2022年春期年会, Ｘ線分光撮像衛星XRISMの観測データ処理とその準備状況, 2022年03月05日, 2022年03月02日, 2022年03月05日, 日本語
• 林克洋; 田代信; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚亮; 佐藤理江; 米山友景; Chris Baluta; 海老沢研; 江口智士; 深澤泰司; 加藤颯; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 佐藤諒平; 志達めぐみ; 菅原泰晴; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; 内田悠介; 内山秀樹; 山内茂雄, 日本天文学会2022年春期年会, X 線分光撮像衛星XRISMの科学運用準備の現状, 2022年03月05日, 2022年03月02日, 2022年03月05日, 日本語
• 柴田実桜; 太田直美; 北山哲; 小松英一郎; 赤堀卓也; 永吉賢一郎; 上田周太朗, 日本天文学会2022年春期年会, NuSTAR衛星によるRX J1347.5–1145銀河団の硬X線観測, 2022年03月02日, 2022年03月02日, 2022年03月05日, 日本語
• 橋口葵; 鳥羽儀樹; 太田直美; 大栗真宗; 上田佳宏; 他 HSC projectメンバー, 日本天文学会2022年春期年会, すばる望遠鏡を用いた銀河団中のAGN fraction分布の調査, 2022年03月02日, 2022年03月02日, 2022年03月05日, 日本語
• 佐藤浩介; 山崎典子; 石田学; 前田良知; 満田和久; 三石郁之; 田原譲; 石崎欣尚; 江副祐一郎; 藤田裕; 藤本龍一; 鶴剛; 大里健; 太田直美; 永井大輔; 吉川耕司; 河合誠之; 松下恭子; 山田真也; 一戸悠人; 内田悠介; 中島裕貴, 日本天文学会2021年秋期年会, ダークバリオン探査ミッションSuper DIOSの開発へ向けた検討 VIII, 2021年09月14日, 2021年09月13日, 2021年09月15日, 日本語
• 鳥羽儀樹; 鳥羽儀樹; 守屋碧; 太田直美; 山田智史; 城知磨; 松林和也; 橋口葵; 柴田実桜; 美里らな; 上田佳宏, 日本天文学会2021年秋期年会, せいめい望遠鏡KOOLS-IFU可視面分光観測で探るNGC7674のAGN活動, 2021年09月13日, 2021年09月13日, 2021年09月15日, 日本語
• 森浩二; 武田彩希; 村上弘志; 寺田幸功; 久保田あや; 榎戸輝揚; 馬場彩; 小高裕和; 谷津陽一; 小林翔悟; 幸村孝由; 萩野浩一; 内山泰伸; 佐藤寿紀; 北山哲; 高橋忠幸; 高橋忠幸; 石田学; 渡辺伸; 山口弘悦; 藤田裕; 中嶋大; 中澤知洋; 古澤彰浩; 鶴剛; 上田佳宏; 内田裕之; 田中孝明; 鈴木寛大; 松本浩典; 野田博文; 常深博; 伊藤真之; 信川正順; 信川久実子; 太田直美; 粟木久光; 寺島雄一; 深沢泰司; 水野恒史; 高橋弘充; 大野雅功; 赤松弘規; HORNSCHEMEIER A.E; 岡島崇; ZHANG W.W., 日本天文学会年会講演予稿集, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画FORCEの現状(12), 2021年09月13日, 2021年09月13日, 2021年09月15日, 日本語
• 中澤知洋; 森浩二; 鶴剛; 上田佳宏; 石田学; 松本浩典; 粟木久光; 村上弘志; 寺田幸功; 久保田あや; 榎戸輝揚; 馬場彩; 小高裕和; 谷津陽一; 小林翔悟; 幸村孝由; 萩野浩一; 内山泰伸; 北山哲; 高橋忠幸; 渡辺伸; 飯塚亮; 山口弘悦; 大橋隆哉; 中嶋大; 古澤彰浩; 田中孝明; 内田裕之; 野田博文; 常深博; 伊藤真之; 信川正順; 信川久実子; 太田直美; 寺島雄一; 深沢泰司; 水野恒史; 高橋弘充; 大野雅功; 赤松弘規; HORNSCHEMEIER A.E; 岡島崇; ZHANG W.W., 日本物理学会講演概要集(CD-ROM), 広帯域X線の高感度観測衛星FORCE:ミッション提案とサイエンス目的の深化, 2020年, 2020年, 2020年, その他
• 清水里紗; 佐藤浩介; 岡部信広; 松下恭子; 太田直美; 田村隆幸, 日本天文学会年会講演予稿集, X線天文衛星XMM-Newtonを用いたAbell2147銀河団の力学的進化の解明, 2020年, 2020年, 2020年, その他
• 森浩二; 武田彩希; 村上弘志; 寺田幸功; 久保田あや; 山田智史; 馬場彩; 小高裕和; 谷津陽一; 小林翔悟; 幸村孝由; 内山泰伸; 佐藤寿紀; 北 山哲; 高橋忠幸; カブリ IPMU; 石田学; 渡辺伸; 山口弘悦; ISAS; JAXA; 藤田裕; 中嶋 大; 萩野浩一; 中澤知洋; 古澤彰浩; 鶴剛; 上田佳宏; 内田裕之; 榎戸輝揚; 水本 岬希; 田中孝明; 鈴木寛大; 松本浩典; 野田博文; 常深博; 伊藤真之; 信川正順; 信川久実子; 太田直美; 粟木久光; 寺島雄一; 志達めぐみ; 深沢泰司; 水 野恒史; 高橋弘充; 谷本敦; 赤松弘規; SRON; Hornschemeier,Ann.E; Okajima,Takashi; Zhang,W.William; Venters,Tonia; Yukita,Mihoko; NASA/GSFC; 他 FORCE WG, 日本天文学会2023年春季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画 FORCE の現状 (15), 2023年03月15日, 2023年03月13日, 2023年03月16日, 日本語
• 山田智史; 田代信; 寺田幸功; ISAS/JAXA; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚 亮; 佐藤理江; 林克洋; 米山友景; 吉田鉄生; ISAS; JAXA; Chris Baluta; NASA; GSFC; 海老沢研; ISAS; JAXA; 江口智士; 深澤泰司; 橋口葵; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志 達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内 田和海; SAS; AXA; 内田悠介; 内山秀樹; 山内茂雄, 日本天文学会2023年春季年会, X線分光撮像衛星 XRISM の観測データ処理ツールの開発状況, 2023年03月14日, 2023年03月13日, 2023年03月16日, 日本語
• 林克洋 (ISAS; JAXA; 田代信; 寺田幸功; ISAS/JAXA; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺 伸; 飯塚亮; 佐藤理江; 米山友景; 吉田鉄生; ISAS; JAXA; Chris Baluta(NASA; GSFC; 海老沢研; ISAS; JAXA; 江口智士; 深澤泰司; 橋口葵; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志 達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内 田和海; SAS; AXA; 内田悠介; 内山秀樹; 山田智史; 山内茂雄, 日本天文学会2023年春季年会, X 線分光撮像衛星 XRISM の科学運用に向けての模擬試験, 2023年03月14日, 2023年03月13日, 2023年03月16日, 日本語
• 米山友景; 田代信; 寺田幸功; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡 辺伸; 飯塚亮; 佐藤理江; 林克洋; 吉田鉄生; ISAS; JAXA; Chris Baluta; 海老沢研; 江口智士; 深澤泰司; 橋口葵; 勝田哲; 北口貴雄; 小高裕和; 大野雅功; 太田直美; 阪間美南; 阪本菜月; 志達めぐみ; 塩入匠; 丹波翼; 谷本敦; 寺島雄一; 坪井陽子; 内 田和海; SAS; AXA; 内田悠介; 内山秀樹; 山田智史; 山内茂雄, 日本天文学会2023年春季年会, X 線分光撮像衛星 XRISM の科学運用準備の現状 (2), 2023年03月14日, 2023年03月13日, 2023年03月16日, 日本語
• Yoshiki Toba; Satoshi Yamada; Kazuya Matsubayashi; Shuhei Koyama; Koki Terao; Hideyuki Izumiura; Hiroyuki Maehara; Aoi Moriya; Aoi Hashiguchi; Naomi Ota; Mio Shibata; Anri Yanagawa; ara Women’s; Yoshihiro Ueda; Kouji Ohta; Shoji Ogawa; yoto; Naoki Yonekura; Tohru Nagao; Masaru Kajisawa; Yoshiki Matsuoka; Masayuki Akiyama; Akatoki Noboriguchi; collaborators, 日本天文学会2023年春季年会, Optical IFU Observations of GOALS Sample with KOOLS-IFU on Seimei Tele- scope: Initial results of 9 U/LIRGs at z < 0.04, 2023年03月13日, 2023年03月13日, 2023年03月16日, 日本語
• 橋口葵, 鳥羽儀樹, 太田直美, 大栗真宗, 上田佳宏, 他HSC project 364メンバー, Tracing the SMBH growth: outlook beyond the HSC-SSP, and future collaborations, AGN fraction distribution in the galaxy clusters selected with the Subaru HSC, 2022年12月01日, 2022年11月30日, 2022年12月02日, 英語
• 森浩二; 武田彩希; 村上弘志; 寺田幸功; 久保田あや; 榎戸輝揚; 馬場 彩; 小高裕和; 谷本敦; 谷津陽一; 小林翔悟; 幸村孝由; 内山泰伸; 佐藤寿紀; 北山哲; 高橋忠幸; カブリ IPMU; 石田学; 渡辺伸; 山口弘悦; ISAS; JAXA; 藤田裕; 中嶋 大; 萩野浩一; 中澤知洋; 古澤彰浩; 鶴剛; 上田佳宏; 内田裕之; 水本岬希; 田中孝明; 鈴木寛大; 松本浩典; 野田博文; 常深博; 伊藤真之; 信川正順; 信川久 実子; 太田直美; 粟木久光; 寺島雄一; 志達めぐみ; 深沢泰司; 水野恒史; 高橋弘充; 赤松弘規; SRON; Hornschemeier,A.E; 岡島崇; Zhang,W.W; Venters,T; Yukita,M.(NASA; GSFC; 他 FORCE WG, 日本天文学会2022秋季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画 FORCE の現状 (14), 2022年09月15日, 2022年09月13日, 2022年09月15日, 日本語
• 柳川晏里; 鳥羽義樹; 太田直美; 他 HSC projectメンバー, 日本天文学会2022秋季年会, すばる望遠鏡Hyper Suprime-Camで探る銀河団メンバー銀河の形態と環境効果, 2022年09月13日, 2022年09月13日, 2022年09月15日, 日本語
• 吉本愛使; 太田直美; 三石郁之; 作田皓基; 大栗真宗; 岡部信広; 鳥羽儀樹; 浜名崇; 宮崎聡; 他 HSC銀河団コラボレーション, 日本天文学会2022秋季年会, HSC-SSP領域にある高赤方偏移銀河団のスケーリング関係と力学的進化, 2022年09月13日, 2022年09月13日, 2022年09月15日, 日本語

  共同研究・競争的資金等URL
• 森浩二, 国内, 日本天文学会2022年秋季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画 FORCEの現状 (14), 口頭発表（一般）, 2022年09月13日, 2022年09月15日, 日本語
• 柳川晏里, 国内, 日本天文学会2022年秋季年会, すばる望遠鏡Hyper Suprime-Camで探る銀河団メンバー銀河の形態と環境効果, 口頭発表（一般）, 2022年09月13日, 2022年09月15日, 日本語
• 林克洋, 国内, 日本天文学会2023年春季年会, X線分光撮像衛星 XRISM の科学運用に向けての模擬試験, 口頭発表（一般）, 2023年03月13日, 2023年03月16日, 日本語
• 森浩二, 国内, 日本天文学会2023年春季年会, 軟X線から硬X線の広帯域を高感度で撮像分光する衛星計画 FORCE の現状 (15), 口頭発表（一般）, 2023年03月13日, 2023年03月16日, 日本語
• 山田智史, 国内, 日本天文学会2023年春季年会, X線分光撮像衛星 XRISM の観測データ処理ツールの開発状況, 口頭発表（一般）, 2023年03月13日, 2023年03月16日, 日本語
• 米山友景, 国内, 日本天文学会2023年春季年会, X線分光撮像衛星 XRISM の科学運用準備の現状 (2), 口頭発表（一般）, 2023年03月13日, 2023年03月16日, 日本語
• 鳥羽儀樹, 国内, 日本天文学会2023年春季年会, Optical IFU Observations of GOALS Sample with KOOLS-IFU on Seimei Telescope: Initial results of 9 U/LIRGs at z < 0.04, 口頭発表（一般）, 2023年03月13日, 2023年03月16日, 日本語
• 小川翔司; ISAS/JAXA; 寺田幸功; 田代信; 埼玉大; JAXA; 高橋弘充; 水野恒史; 深沢泰司; 阪本 菜月; 信川正順; 宇野伸一郎; 中澤知洋; 大宮 悠希; 大熊佳吾; 内山秀樹; 久保田あや; 勝田哲; 塩入匠; 寺島雄一; 志達めぐ み; 新居田祐基; 山内茂雄; 太田直美; 白木天音; 鈴木那梨; 北口貴雄; 山田智史; 坪井陽子; 米山友景; 根本登; 内田悠介; 江口智士; 谷本敦; 善本真梨那; 海老沢研; 渡辺伸; 飯塚亮; 林克洋; 内田和海; 金丸善朗; 星野晶夫; 吉田鉄生; ISAS; JAXA; Matt Holland; Tahir Yaqoob; Chris Baluta (NASA; Michael Loewenstein (NASA; University of Maryland; Eric Miller; Massachusetts Institute of Technology, 日本天文学会2024年春季年会, X線分光撮像衛星XRISMの科学運用の現状, 2024年03月13日, 2024年03月11日, 2024年03月15日, 日本語
• 林克洋 (ISAS; JAXA; 田代信; 寺田幸功; ISAS/JAXA; 高橋弘充; 信川正順; 水野恒史; 宇野伸一郎; 久保田あや; 中澤知洋; 渡辺伸; 飯塚 亮; 佐藤理江; 星野晶夫; 吉田鉄生; 小川翔司; 金丸善朗; ISAS; JAXA; Chris Baluta(NASA; GSFC; 海老沢研; ISAS; JAXA; 江口智士; 小高裕和; 勝田哲; 北口貴雄; 新 居田祐基; 太田直美; 阪本菜月; 志達めぐみ; 塩入匠; 白木天音; 谷本敦; 寺島雄一; 坪井陽子; 内田和海; ISAS; JAXA; 内田悠介; 内山秀樹; 山田智史; 山内茂雄; 米山友景, 日本天文学会2023年秋季年会, X線分光撮像衛星XRISMの科学運用準備の現状 (3), 2023年09月20日, 2023年09月20日, 2023年09月22日, 日本語
• Miller, Eric; Ota, Naomi; Eckert, Dominique; search by orcid; Ettori, Stefano; Kelley, Richard; McNamara, Brian; Markevitch, Maxim; Sarkar, Arnab; Simionescu, Aurora; Szymkowiak, Andrew; Uchida, Yuusuke; Xrism Science Team, AAS High Energy Astrophysics Division meeting #20, Galaxy cluster cosmology and astrophysics with XRISM, 2023年09月, 英語

共同研究・競争的資金等の研究課題

• 2021年度日独共同研究奨学金, 2021年09月01日, 2022年08月31日, 研究代表者, 宇宙X線望遠鏡eROSITAとXRISMによる銀河団ガスと活動銀河核の相互作用の研究, 日本フンボルト協会, 日独共同研究奨学金
• 超高分解能Ｘ線カロリメータの開発実験, 0, 0, 0, 競争的資金
• 銀河団の構造進化の観測的研究, 0, 0, 0, 競争的資金
• Development experiment of High-resolution X-ray spectrometers, 0, 0, 0, 競争的資金
• Observational study of structure and evolution of galaxy clusters, 0, 0, 0, 競争的資金
• 基盤研究(C), 2020年04月01日, 2025年03月31日, 20K04027, eROSITA全天サーベイによる銀河団のＸ線解析と宇宙論への応用, 太田 直美, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4550000, 3500000, 1050000, 銀河団は宇宙最大の天体であり、その形成や進化を理解することは、宇宙そのものの進化を理解することに役立つ。どのような質量の銀河団がいくつあるかを 様々な距離に渡って精密に測定できれば、宇宙論モデルに制限をつけることができる。特に、最大の謎であるダークエネルギー の性質の解明に向けて新たな手がかりが得られると期待される。本研究では、SRG衛星搭載eROSITA検出器による過去最大のX線全天サーベイを利用して、多数の銀河団のX線データを統一的に解析し、高精度の質量関数測定を実現することを目的とする。これまで、X線領域で精度のよい質量測定を阻んできたのは、銀河団内部の複雑なガス進化に由来するスケーリング則の分散である。そこで、主成分分析から分散の物理起源を特定して取り除き、さらに遠方天体についても同様の解析を行ったうえで、広い赤方偏移範囲に適用可能な質量推定法の確立を目指す。今年度は、eROSITAとすばる望遠鏡Hyper Suprime-Cam(HSC)が共同で行った初期サーベイ領域について、可視銀河団の詳細なX線データ解析を行い、弱い重力レンズ効果と比較した。特に、リッチネスが40を超える大規模な銀河団43天体を対象に、X線スペクトル解析から温度光度関係や質量光度関係をはじめとするスケーリング則を導出した。また、X線イメージ解析から、高温ガスのX線輝度ピークと中心銀河の位置のずれを求め、銀河団の力学状態を推定した。その結果、X線銀河団サンプルに比べて可視銀河団は、不規則銀河団の割合が大きいことや光度温度関係の傾きが小さい傾向があることを見つけた。この観測成果に理論モデルとの比較に基づいた考察を加えて、主著論文を投稿予定である。, kaken;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:presentations

  対象リソースIRI
• 基盤研究(C), 2016年04月01日, 2019年03月31日, 16K05295, 精密Ｘ線分光による銀河団ガスの速度構造の研究, 太田 直美, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4550000, 3500000, 1050000, 銀河団は宇宙最大の天体であり、その中に存在する複雑なガス運動に由来する圧力が、ダークマターの質量を推定する上で最大の不定性の要因になっている。ひとみ衛星によりペルセウス座銀河団中心部のガス乱流の直接測定に成功し、それに由来する圧力が小さいことを示した。将来の本格的なＸ線詳細分光に備えて模擬観測を実施し、ガス運動の場所ごとのばらつきや、ダークマター質量をいかに正確に求められるかを検討した。また、すばる望遠鏡のサーベイによって新しく見つかった銀河団のＸ線観測データを系統的に解析し、天体の形態や温度と光度の関係およびその進化を調査し、既存の単純な理論モデルでは観測結果を説明できないことを示した。, url;kaken

  対象リソースIRI
• 国際共同研究加速基金（国際共同研究強化）, 2017年, 2019年, 16KK0101, 大規模Ｘ線サーベイによる銀河団質量関数の構築（国際共同研究強化）, 太田 直美, 日本学術振興会, 科学研究費助成事業 国際共同研究加速基金（国際共同研究強化）, 奈良女子大学, 13260000, 10200000, 3060000, kaken;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:media_coverage

  対象リソースIRI
• 基盤研究(A), 2013年04月01日, 2017年03月31日, 25247028, X線マイクロカロリメータで探る宇宙のダークサイド, 満田 和久; 藤本 龍一; 太田 直美, 日本学術振興会, 科学研究費助成事業 基盤研究(A), 国立研究開発法人宇宙航空研究開発機構, 43290000, 33300000, 9990000, 世界最先端のX線分光観測装置SXSから最大限の性能を引き出すための研究とその最大限の性能によって達成可能となるサイエンスについて従来の観測装置も用いた準備研究を行なった。ASTRO-H衛星の不具合のためSXSは短い期間の観測となったが，その間，想定通りに完璧に動作し，銀河団観測からダークエネルギーに関する制限を得る際に問題となる銀河団内高温物質の運動の影響が小さい示唆を得るなどの科学成果を得た。また，すざく衛星を用いたX線観測による暗黒物質探査の可能性を調べ，銀河ハローからの0.5から10keVの輝線放射の上限からステライルニュートリノについてこの質量範囲で，これまでで最も厳しい制限をえた。, url;kaken

  対象リソースIRI
• 基盤研究(C), 2013年04月01日, 2016年03月31日, 25400231, 銀河団の形成進化におけるエネルギー収支の解明, 太田 直美, 日本学術振興会, 科学研究費助成事業 基盤研究(C), 奈良女子大学, 4420000, 3400000, 1020000, 銀河団は衝突合体を繰り返し、今もなお成長を続ける天体である。衝突の莫大な運動エネルギーは、銀河団中のガスを激しく加熱したり、複雑な運動を生んだりすることに使われる。このような銀河団形成に伴うエネルギー収支を理解することを目指して、主に「すざく」衛星のＸ線データを系統的に分析し、超高温ガスや非熱的ガスの存在に制限をつけた。また、近傍銀河団のガス運動探査を行い、規則型・不規則型銀河団の両方にガス運動が存在する兆候やガスと銀河の分布の違いを新たに見つけた。また、ASTRO-H衛星搭載Ｘ線カロリメータによる精密分光のシミュレーションを行い、ガス運動や銀河団質量が精度良く再現できることを示した。, url;kaken

  対象リソースIRI
• 若手研究(B), 2010年, 2012年, 22740124, 銀河団超高温ガスの探査, 太田 直美, 日本学術振興会, 科学研究費助成事業 若手研究(B), 奈良女子大学, 3900000, 3000000, 900000, 銀河団の進化の解明を目指して、「すざく」衛星の広帯域X線分光データの解析を行った。複数の銀河団において、天体同士の衝突合体に伴って作られた超高温のガスの存在を確認した。一方、高エネルギー粒子からの非熱的硬X線放射は検出されず、従来よりも厳密な制限を得ることに成功した。さらに、準静水圧平衡の条件のもとで放射冷却下にある銀河団ガスの密度分布を計算し、観測との比較を示した。, url;kaken

  対象リソースIRI
• 若手研究(B), 2007年, 2009年, 19740112, X線分光を用いた銀河団ガスの運動の探査, 太田 直美, 日本学術振興会, 科学研究費助成事業 若手研究(B), 東京理科大学, 3080000, 2600000, 480000, 宇宙最大の天体である銀河団のダイナミックな進化を解明することを目指して、「すざく」衛星を用いたX線観測を行った。銀河団中にはX線を放射する高温ガスが大量に含まれており、その運動や温度を詳細に測定できる。特に、銀河団RXJ1347中に3億度という宇宙で最も熱いガスの存在を初めてX線観測のみから確認することに成功した。これは2つの銀河団が数千キロメートル毎秒にもおよぶ高速で衝突合体したことによって生成された可能性が高い。, url;kaken

  対象リソースIRI
• 特別研究員奨励費, 2001年, 2003年, 01J02299, 銀河団の力学的進化の観測的研究, 太田 直美, 日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 東京都立大学, 3900000, 3900000, X線天文衛星「あすか」および「ローサット」によって観測された79個の遠方銀河団のX線データ解析結果に基づいて、銀河団高温ガスの性質の統計的解析を行った。特に、温度とガス密度分布の相関や、ガス質量とダークマター質量の比(ガス質量比)の赤方偏移依存性について詳細に調べた。これより、第一に温度とガス密度分布の空間的広がりを特徴づけるコア半径の間には明らかな相関がないことがわかった。一方で、温度とX線光度の間の相関関係(いわゆる光度温度関係)には、コア半径により有意な違いが見られた。このことは、銀河団中の物質の空間分布を記述する際に従来用いられてきたSelf-similarの仮定が、現実の銀河団においては成り立っていないことを示している。また第二に、ガス質量比について79個の銀河団の平均値が、0.27±0.11と求められた。さらにこの値の推定における、銀河団の形成時期の仮定の影響について検討した結果、多くの銀河団が赤方偏移1.5で形成されたと考えると、銀河団中のガス質量比と宇宙全体のバリオン比がよく一致することがわかった。このことは、銀河団が現在考えられているよりも大きな赤方偏移でおこった可能性を示唆している。以上の研究結果を投稿論文としてまとめた。 また、野辺山45m電波望遠鏡を用いて銀河団RDCS0910のスニヤエフゼルドヴィッチ効果(SZ効果)の観測を行った。この天体は赤方偏移1.1に位置する超遠方銀河団であり、過去のX線観測から近傍銀河団と同程度の温度、質量をもつ高温ガスの存在が示唆されている。この天体からSZ効果の信号が検出されれば、電波で観測された最遠方の銀河団となるばかりか、銀河団ガスの進化を理解するうえで重要な手がかりが得られると期待される。今年度この天体の20時間の観測データを蓄横することができた。現在この天体からのSZ効果初検出を目指してデータ解析を進めている。, kaken

  対象リソースIRI
• 特別研究員奨励費, 1998年, 2000年, 98J05075, X線による遠方銀河団の観測的研究, 太田 直美, 日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 東京大学, 2700000, 2700000, kaken

  対象リソースIRI
• 2021年10月, 2022年09月, 研究代表者, 宇宙Ｘ線望遠鏡eROSITAとXRISMによる銀河団ガスと活動銀河核の相互作用の研究, Angie Veronica, 日本フンボルト協会, 日独共同研究奨学金, 奈良女子大学
• 基盤研究(A), 2023年04月01日, 2028年03月31日, 23H00121, 超広帯域サブミリ波多色観測で探る銀河団の動的描像, 大島 泰; 竹腰 達哉; 田井野 徹; 太田 直美; 美馬 覚, 日本学術振興会, 科学研究費助成事業, 国立天文台, 46540000, 35800000, 10740000, kaken

  対象リソースIRI

Ⅲ．社会連携活動実績

１．公的団体の委員等（審議会、国家試験委員、他大学評価委員，科研費審査委員等）

• アテナ衛星サイエンスワーキンググループ1 共同議長, 2021年01月, 9999年, その他
• アテナ衛星サイエンスワーキンググループ1.1 共同議長, 2015年02月, 2020年12月, その他
• XRISM衛星, 銀河団ワーキンググループ共同議長, 2019年, 9999年, その他

２． 学外非常勤講師等

• 放送大学奈良学習センター, 銀河や暗黒物質の織りなす宇宙