研究者総覧

太田 直美 (オオタ ナオミ)

  • 研究院自然科学系物理学領域 准教授
Last Updated :2021/10/23

researchmap

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線分光 

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

委員歴

  • 2021年01月 アテナ衛星サイエンスワーキンググループ1 共同議長 others

    その他

  • 2015年02月 - 2020年12月 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 others

    その他

論文

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 71 (4), doi;web_of_science

    研究論文(学術雑誌)

  • 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, Proc. SPIE 10699, Space Telescopes and Instrumentation 2018: Ultraviolet to Gamma Ray, doi

    研究論文(国際会議プロシーディングス)

  • 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, JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS, 4 (2), 021402, doi;web_of_science;scopus;scopus_citedby

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), id.15, doi;web_of_science;scopus;scopus_citedby

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (3), id.S22, doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (SP1), id.S27, doi;web_of_science

    研究論文(学術雑誌)

  • 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, NATURE, 551 (7681), 478 - +, doi;web_of_science

    研究論文(学術雑誌)

  • 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, Astrophysical Journal, 782 (1), doi

    研究論文(学術雑誌)

  • 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, Publications of the Astronomical Society of Japan, 64 (4), 90, doi

    研究論文(学術雑誌)

  • 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, Publications of the Astronomical Society of Japan, 59 (2), 299 - 317, doi

    研究論文(学術雑誌)

  • 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, IEEE Nuclear Science Symposium Conference Record, 4, 2526 - 2531, doi;url

    研究論文(国際会議プロシーディングス)

  • 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, PROCEEDINGS OF THE IAU 8TH ASIAN-PACIFIC REGIONAL MEETING, VOL I, 289, 465 - 468, web_of_science

    研究論文(国際会議プロシーディングス)

  • 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, IEEE Nuclear Science Symposium and Medical Imaging Conference, 1, url;url;scopus_citedby

    研究論文(国際会議プロシーディングス)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 69 (3), id.39, doi;web_of_science

    研究論文(学術雑誌)

  • 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, NATURE, 535 (7610), 117 - +, doi;web_of_science

    研究論文(学術雑誌)

  • 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, ASTRONOMY & ASTROPHYSICS, 562, id. A11, 6pp, doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 72 (1), doi;web_of_science

    研究論文(学術雑誌)

  • 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, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 491 (3), 3411 - 3418, doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (6), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (6), doi;web_of_science

    研究論文(学術雑誌)

  • 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, ASTRONOMY & ASTROPHYSICS, 619, doi;web_of_science

    研究論文(学術雑誌)

  • 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, ASTROPHYSICAL JOURNAL, 866 (1), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (3), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (3), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (3), doi;web_of_science

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (3), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 70, doi;web_of_science

    研究論文(学術雑誌)

  • 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, SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY, 10699, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 69 (6), doi;web_of_science

    研究論文(学術雑誌)

  • 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, ASTROPHYSICAL JOURNAL, 845 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 68 (5), doi;web_of_science

    研究論文(学術雑誌)

  • 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, SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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, SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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, SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY, 9905, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 66 (5), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 66 (1), doi;web_of_science

    研究論文(学術雑誌)

  • 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, SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, 9144, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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, SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY, 9144, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 65 (5), doi;web_of_science

    研究論文(学術雑誌)

  • 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, ASTROPHYSICAL JOURNAL, 766 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 65 (2), doi;web_of_science

    研究論文(学術雑誌)

  • 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, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 429 (1), 482 - 493, doi;web_of_science

    研究論文(学術雑誌)

  • 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, VETERINARY PARASITOLOGY, 190 (3-4), 401 - 410, doi;web_of_science

    研究論文(学術雑誌)

  • 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, ASTROPHYSICAL JOURNAL, 758 (1), doi;web_of_science

    研究論文(学術雑誌)

  • 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, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 64 (5), doi;web_of_science

    研究論文(学術雑誌)

  • 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, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 436 (1-2), 291 - 296, doi;web_of_science

    研究論文(学術雑誌)

  • 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, HARD X-RAY AND GAMMA-RAY DETECTOR PHYSICS, OPTICS, AND APPLICATIONS, 3115, 244 - 253, doi;web_of_science

    研究論文(国際会議プロシーディングス)

  • 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03月23日, arxiv;url;url

    研究論文(学術雑誌)

  • 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, Astronomy & Astrophysics, 647, A2 - A2, doi;url;rm:research_project_id

    研究論文(学術雑誌)

  • 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

    ABSTRACT 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, Monthly Notices of the Royal Astronomical Society, 501 (2), 1701 - 1732, doi;url;url

    研究論文(学術雑誌)

  • 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

    2020年12月13日, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, doi

    研究論文(国際会議プロシーディングス)

  • 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年12月13日, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, doi

    研究論文(国際会議プロシーディングス)

  • 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年12月13日, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, doi

    研究論文(国際会議プロシーディングス)

  • 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, Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray, doi

    研究論文(国際会議プロシーディングス)

  • 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

    2021年08月04日, Publications of the Astronomical Society of Japan, doi;rm:research_project_id

    研究論文(学術雑誌)

  • 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, IEEE Transactions on Nuclear Science, 48 (3 I), 426 - 429, doi;scopus;scopus_citedby

    研究論文(国際会議プロシーディングス)

MISC

  • 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, 日本天文学会年会講演予稿集, 2017, 186, j_global;url

  • 「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, 日本天文学会年会講演予稿集, 2017, 186, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2016, 187, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2016, 150, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2014, 225, j_global;url

  • Search for Very Hot/Non-Thermal Emission and Gas Bulk Motions in Clusters

    太田 直美

    2014年, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 378 - 381

  • 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, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 400 - 401

  • 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, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 406 - 407

  • 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, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 414 - 415

  • Search for gas bulk motions in eight nearby clusters of galaxies with Suzaku

    Naomi Ota; Hiroko Yoshida

    To search for bulk motions of the intracluster medium, we analyzed X-ray spectra taken with the Suzaku satellite, and measured the Doppler shift of the Fe-K line emission from eight nearby clusters of galaxies with various X-ray morphologies. In the cores of the Centaurus and Perseus clusters, the gas bulk velocity does not exceed the sound velocity, which confirms the results of previous researchs. For the Cen 45 subcluster, we found that the radial velocity relative to the Centaurus core, <780 km s(-1), is significantly smaller than that reported in the optical band at the 3.9 sigma level, which suggests an offset between the gas and galaxy distributions along the line of sight due to the subcluster merger. In A2199, A2142, A3667, and A133, no significant bulk motion was detected, indicating an upper limit on the radial velocity of 3000-4000 km s(-1). A sign of large bulk velocity in excess of the instrumental calibration uncertainty was found near the center of the coolcore cluster A2029 and in a subcluster of the merging cluster A2255, suggesting that the nonthermal pressure support is not negligible in estimating the total gravitational mass of not only merging clusters, but also relaxed clusters, as predicted by numerical simulations. To improve the significance of the detection, however, a further examination by follow-up observations is required. The present study provides a pilot survey prior to future high-resolution spectroscopy with ASTRO-H, which is expected to play a critical role in revealing the dynamical evolutions of clusters., OXFORD UNIV PRESS, 2016年06月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 68, 422 - 423, doi;web_of_science

  • Search for Very Hot/Non-Thermal Emission and Gas Bulk Motions in Clusters

    OTA Naomi

    2014年, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 378 - 381

  • 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, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 400 - 401

  • 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, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 406 - 407

  • 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, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 414 - 415

  • Search for gas bulk motions in eight nearby clusters with Suzaku

    OTA Naomi; Yoshida, Hiroko; Ota, Naomi

    2014年, Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 422 - 423

  • 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, 日本天文学会年会講演予稿集, 2012, 219, j_global;url

  • 「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, 日本天文学会年会講演予稿集, 2012, 221, j_global;url

  • 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., NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES, 2012年08月, RESEARCH IN ASTRONOMY AND ASTROPHYSICS, 12 (8), 973 - 994, doi;web_of_science

  • 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., NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES, 2012年08月, RESEARCH IN ASTRONOMY AND ASTROPHYSICS, 12 (8), 973 - 994, doi;web_of_science

  • 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, 日本天文学会年会講演予稿集, 2012, 233, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2012, 233, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2012, 233, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2012, 89, j_global;url

  • 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., OXFORD UNIV PRESS, 2011年11月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63 (SP3), S1019 - S1033, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2011年11月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63 (SP3), S991 - S1007, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2011年11月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63 (SP3), S979 - S990, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2011年11月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63 (SP3), S1019 - S1033, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2011年11月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63 (SP3), S991 - S1007, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2011年11月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 63 (SP3), S979 - S990, doi;web_of_science

  • 「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, 日本天文学会年会講演予稿集, 2011, 226, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2011, 228, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2011, 186, j_global;url

  • 「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, 日本天文学会年会講演予稿集, 2011, 186, j_global;url

  • 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., EDP SCIENCES S A, 2010年12月, ASTRONOMY & ASTROPHYSICS, 524, doi;web_of_science

  • 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., EDP SCIENCES S A, 2010年12月, ASTRONOMY & ASTROPHYSICS, 524, doi;web_of_science

  • 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., IOP PUBLISHING LTD, 2010年09月, ASTROPHYSICAL JOURNAL, 721 (1), 653 - 669, doi;web_of_science

  • 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., IOP PUBLISHING LTD, 2010年09月, ASTROPHYSICAL JOURNAL, 721 (1), 653 - 669, doi;web_of_science

  • 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, 日本天文学会年会講演予稿集, 2010, 180, j_global;url

  • 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, Proceedings of SPIE - The International Society for Optical Engineering, 7732, 77320Z-77320Z-18, doi;scopus;scopus_citedby

  • 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., SPIE-INT SOC OPTICAL ENGINEERING, 2010年, SPACE TELESCOPES AND INSTRUMENTATION 2010: ULTRAVIOLET TO GAMMA RAY, 7732, 77320Z-77320Z-18, doi;web_of_science;scopus;scopus_citedby

  • 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., IOP PUBLISHING LTD, 2009年08月, ASTROPHYSICAL JOURNAL, 701 (1), 377 - 395, doi;web_of_science

  • 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., IOP PUBLISHING LTD, 2009年08月, ASTROPHYSICAL JOURNAL, 701 (1), 377 - 395, doi;web_of_science

  • 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., EDP SCIENCES S A, 2009年07月, ASTRONOMY & ASTROPHYSICS, 501 (3), 899 - 905, doi;web_of_science

  • 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., EDP SCIENCES S A, 2009年07月, ASTRONOMY & ASTROPHYSICS, 501 (3), 899 - 905, doi;web_of_science

  • 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., IOP PUBLISHING LTD, 2009年04月, ASTROPHYSICAL JOURNAL, 695 (2), 1191 - 1198, doi;web_of_science

  • 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., IOP PUBLISHING LTD, 2009年04月, ASTROPHYSICAL JOURNAL, 695 (2), 1191 - 1198, doi;web_of_science

  • 「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, 日本天文学会年会講演予稿集, 2009, 198, j_global;url

  • 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)., OXFORD UNIV PRESS, 2009年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 61, S377 - S386, doi;web_of_science

  • 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, Publications of the Astronomical Society of Japan, 61, S377-S386

  • 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., WILEY-BLACKWELL, 2008年11月, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 390 (3), 1061 - 1070, doi;web_of_science

  • 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., EDP SCIENCES S A, 2008年11月, ASTRONOMY & ASTROPHYSICS, 491 (2), 363 - 377, doi;web_of_science

  • 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., WILEY-BLACKWELL, 2008年11月, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 390 (3), 1061 - 1070, doi;web_of_science

  • 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., EDP SCIENCES S A, 2008年11月, ASTRONOMY & ASTROPHYSICS, 491 (2), 363 - 377, doi;web_of_science

  • 「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, 日本天文学会年会講演予稿集, 2008, 214, j_global;url

  • 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., OXFORD UNIV PRESS, 2008年02月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 60, S317 - S331, doi;web_of_science

  • 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., SCIENCE PRESS, 2008年, CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS, 8, 84 - 92, web_of_science

  • 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., OXFORD UNIV PRESS, 2008年02月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 60, S317 - S331, doi;web_of_science

  • 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., SCIENCE PRESS, 2008年, CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS, 8, 84 - 92, web_of_science

  • 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., OXFORD UNIV PRESS, 2007年04月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (2), 299 - 317, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年04月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (2), 299 - 317, doi;web_of_science

  • 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

    一般社団法人日本物理学会, 2007年02月28日, 日本物理学会講演概要集, 62 (1), cinii_articles

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59, S351 - S359, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S327 - S338, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S77 - S112, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S35 - S51, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S1 - S7, doi;web_of_science

  • 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, XMM-Newton: The Next Decade

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 312 - 315, web_of_science

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 45 - 48, web_of_science;doi

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 33 - 36, web_of_science

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 25 - 28, web_of_science

  • 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, ESO Astrophysics Symposia, 2007, 398 - 400, doi

  • 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, ESO Astrophysics Symposia, 2007, 389 - 394, doi

  • 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]., SPRINGER-VERLAG BERLIN, 2007年, HEATING VERSUS COOLING IN GALAXIES AND CLUSTERS OF GALAXIES, 112 - +, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59, S351 - S359, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S327 - S338, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S77 - S112, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S35 - S51, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2007年01月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 59 (SP1), S1 - S7, doi;web_of_science

  • 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, XMM-Newton: The Next Decade

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 312 - 315, web_of_science

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 45 - 48, web_of_science;doi

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 33 - 36, web_of_science

  • 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., PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, 2007年, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, 169 (169), 25 - 28, web_of_science

  • 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, ESO Astrophysics Symposia, 2007, 398 - 400, doi

  • 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, ESO Astrophysics Symposia, 2007, 389 - 394, doi

  • 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]., SPRINGER-VERLAG BERLIN, 2007年, HEATING VERSUS COOLING IN GALAXIES AND CLUSTERS OF GALAXIES, 112 - +, doi;web_of_science

  • 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, 日本天文学会年会講演予稿集, 2006, 193, j_global;url

  • 「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, 日本天文学会年会講演予稿集, 2006, 193, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2006, 192, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2006, 193, j_global;url

  • 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

    一般社団法人日本物理学会, 2006年08月18日, 日本物理学会講演概要集, 61 (2), cinii_articles

  • 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

    一般社団法人日本物理学会, 2006年08月18日, 日本物理学会講演概要集, 61 (2), cinii_articles

  • 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., UNIV CHICAGO PRESS, 2006年08月, ASTROPHYSICAL JOURNAL, 647 (1), 215 - 221, doi;web_of_science;url

  • 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., OXFORD UNIV PRESS, 2006年08月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 58 (4), 719 - 742, doi;web_of_science

  • 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, 天文月報, 99 (6), 332 - 333, cinii_articles

  • 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., ELSEVIER SCIENCE BV, 2006年04月, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 559 (2), 617 - 619, doi;web_of_science;url

  • 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., ELSEVIER SCIENCE BV, 2006年04月, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 559 (2), 620 - 622, doi;web_of_science;url

  • 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., ELSEVIER SCIENCE BV, 2006年04月, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 559 (2), 614 - 616, doi;web_of_science

  • 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., UNIV CHICAGO PRESS, 2006年04月, ASTROPHYSICAL JOURNAL, 640 (2), 673 - 690, doi;web_of_science

  • 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., ELSEVIER SCIENCE BV, 2006年04月, NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 559 (2), 614 - 616, doi;web_of_science

  • 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., UNIV CHICAGO PRESS, 2006年04月, ASTROPHYSICAL JOURNAL, 640 (2), 673 - 690, doi;web_of_science

  • 「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, 日本天文学会年会講演予稿集, 2006, 182, j_global;url

  • 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, 日本天文学会年会講演予稿集, 2006, 178, j_global;url

  • 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, The 9th Asian-Pacific Regional IAU Meeting, held in Nusa Dua, Bali, Indonesia, 26-29 July 2005, 243

  • 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, The 9th Asian-Pacific Regional IAU Meeting, held in Nusa Dua, Bali, Indonesia, 26-29 July 2005, 243

  • 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., OXFORD UNIV PRESS, 2006年08月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 58 (4), 719 - 742, doi;web_of_science

  • 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, Astronomy and Astrophysics, 428 (3), 757 - 779, doi

  • 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., EDP SCIENCES S A, 2004年12月, ASTRONOMY & ASTROPHYSICS, 428 (3), 757 - 779, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2004年10月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 56 (5), L29 - L34, doi;web_of_science

    速報,短報,研究ノート等(学術雑誌)

  • 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., OXFORD UNIV PRESS, 2004年10月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 56 (5), 753 - 764, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2004年10月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 56 (5), L29 - L34, doi;web_of_science

    速報,短報,研究ノート等(学術雑誌)

  • 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., OXFORD UNIV PRESS, 2004年10月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 56 (5), 753 - 764, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2004年02月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 56 (1), 17 - 28, doi;web_of_science

  • 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., OXFORD UNIV PRESS, 2004年02月, PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN, 56 (1), 17 - 28, doi;web_of_science

  • 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, 日本天文学会年会講演予稿集, 2004, 204, j_global;url

  • 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., IOP PUBLISHING LTD, 2004年01月, ASTROPHYSICAL JOURNAL, 601 (1), 120 - 132, doi;web_of_science

  • 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, The Astrophysical Journal,, 601 (1), 120 - 132, doi

  • 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, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, 141, doi

  • 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, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, 33

  • A uniform X-ray analysis of 79 distant clusters of galaxies

    N Ota; K Mitsuda

    WILEY-V C H VERLAG GMBH, 2003年, ASTRONOMISCHE NACHRICHTEN, 324 (1-2), 172 - 172, web_of_science

  • Chandra Analysis and Mass Estimation of the Lensing Cluster CL0024+17

    OTA Naomi; Ota, N; Hattori, M; Pointecouteau, E; Mitsuda, K

    2003年, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, 141, doi

  • 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, Workshop on Galaxies and Clusters of Galaxies, Proceedings of the workshop held at Shuzenji, 33

  • A uniform X-ray analysis of 79 distant clusters of galaxies

    OTA Naomi; Ota, N; Mitsuda, K

    2003年, Astronomische Nachrichten, 324 (1-2), 172

  • 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., UNIV CHICAGO PRESS, 2002年03月, ASTROPHYSICAL JOURNAL, 567 (1), L23 - L26, doi;web_of_science

  • Two Classes of Cluster Size and the Connection to the L-T Relation

    太田 直美; Ota, N; Mitsuda, K

    2002年, New Trends in Theoretical and Observational Cosmology, Proceedings of the 5th RESCEU International Symposium, 337

  • 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)., ASTRONOMICAL SOC PACIFIC, 2002年, TRACING COSMIC EVOLUTION WITH GALAXY CLUSTERS, PROCEEDINGS, 268, 423 - 424, web_of_science

  • 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, The Proceedings of the IAU 8th Asian-Pacific Regional Meeting, II, 287 - 288

  • X-Ray Study of 79 Distant Clusters of Galaxies: Discovery of Two Classes of Cluster Size

    OTA Naomi; Ota, N; Mitsuda, K

    2002年, The Astrophysical Journal, 567 (1), L23-L26, doi

  • Two Classes of Cluster Size and the Connection to the L-T Relation

    OTA Naomi; Ota, N; Mitsuda, K

    2002年, New Trends in Theoretical and Observational Cosmology, Proceedings of the 5th RESCEU International Symposium, 337

  • 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)., ASTRONOMICAL SOC PACIFIC, 2002年, TRACING COSMIC EVOLUTION WITH GALAXY CLUSTERS, PROCEEDINGS, 268, 423 - 424, web_of_science

  • 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, The Proceedings of the IAU 8th Asian-Pacific Regional Meeting, II, 287 - 288

  • 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., UNIV CHICAGO PRESS, 2001年04月, ASTROPHYSICAL JOURNAL, 551 (2), 929 - 933, doi;web_of_science

  • 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., UNIV CHICAGO PRESS, 2001年04月, ASTROPHYSICAL JOURNAL, 551 (2), 929 - 933, doi;web_of_science

  • Iron Emission Line from the Galaxy Cluster Including the Lensing Radio Galaxy 3C220.1 at z = 0.62

    太田 直美; Ota, N; Mitsuda, K; Hattori, M; Mihara, T

    2001年, Gravitational Lensing: Recent Progress and Future Goals, ASP Conference Proceedings, 237, 333

  • 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, The Astrophysical Journal, 563 (2), L103-L106, doi

  • X-ray Study of Distant Clusters of Galaxies: Structure and Evolution

    太田 直美; Ota, N; Mitsuda, K

    2001年, New Century of X-ray Astronomy, ASP Conference Proceedings, 251, 478

  • Probing Distant Universe X-ray Sources with Gravitational Lensing

    太田 直美; Oshima, T; Mitsuda, K; Ota, N; Futamoto, K; Hattori, M; Yonehara, A; Sekimoto, Y; Mihara, T; Ikebe, Y; Kneib, J. P; Miralles, J. M

    2001年, New Century of X-ray Astronomy, ASP Conference Proceedings, 251, 476

  • Structure of Clusters of Galaxies Inferred from a Large Sample of ROSAT and ASCA Observations

    太田 直美; Mitsuda, K; Ota, N

    2001年, New Century of X-ray Astronomy, ASP Conference Proceedings, 251, 164

  • Iron Emission Line from the Galaxy Cluster Including the Lensing Radio Galaxy 3C220.1 at z = 0.62

    OTA Naomi; Ota, N; Mitsuda, K; Hattori, M; Mihara, T

    2001年, Gravitational Lensing: Recent Progress and Future Goals, ASP Conference Proceedings, 237, 333

  • Detection of an Iron Emission Feature from the Lensed Broad Absorption Line QSO H1413+117 at z = 2.56

    OTA Naomi; 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, The Astrophysical Journal, 563 (2), L103-L106, doi

  • X-ray Study of Distant Clusters of Galaxies: Structure and Evolution

    OTA Naomi; Ota, N; Mitsuda, K

    2001年, New Century of X-ray Astronomy, ASP Conference Proceedings, 251, 478

  • Probing Distant Universe X-ray Sources with Gravitational Lensing

    OTA Naomi; Oshima, T; Mitsuda, K; Ota, N; Futamoto, K; Hattori, M; Yonehara, A; Sekimoto, Y; Mihara, T; Ikebe, Y; Kneib, J. P; Miralles, J. M

    2001年, New Century of X-ray Astronomy, ASP Conference Proceedings, 251, 476

  • Structure of Clusters of Galaxies Inferred from a Large Sample of ROSAT and ASCA Observations

    OTA Naomi; Mitsuda, K; Ota, N

    2001年, New Century of X-ray Astronomy, ASP Conference Proceedings, 251, 164

  • 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., EDP SCIENCES S A, 2000年03月, ASTRONOMY & ASTROPHYSICS, 355 (2), 433 - 442, web_of_science

  • 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., EDP SCIENCES S A, 2000年03月, ASTRONOMY & ASTROPHYSICS, 355 (2), 433 - 442, web_of_science

  • 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., UNIV CHICAGO PRESS, 2000年02月, ASTROPHYSICAL JOURNAL, 530 (1), 172 - 176, web_of_science

  • 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., UNIV CHICAGO PRESS, 2000年02月, ASTROPHYSICAL JOURNAL, 530 (1), 172 - 176, web_of_science

  • 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, 日本天文学会年会講演予稿集, 2000, 178, j_global;url

  • 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., PERGAMON PRESS LTD, 2000年, BROAD BAND X-RAY SPECTRA OF COSMIC SOURCES, 25 (3-4), 789 - 792, web_of_science

  • 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., PERGAMON PRESS LTD, 2000年, BROAD BAND X-RAY SPECTRA OF COSMIC SOURCES, 25 (3-4), 789 - 792, web_of_science

  • 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., Elsevier Ltd, 2000年, Advances in Space Research, 25 (3-4), 789 - 792, doi

  • 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., SPIE-INT SOC OPTICAL ENGINEERING, 1999年, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY X, 3765, 645 - 663, web_of_science

  • Detection of Iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1

    N Ota; K Mitsuda; M Hattori; T Mihara

    WILEY-V C H VERLAG GMBH, 1999年, ASTRONOMISCHE NACHRICHTEN, 320 (4-5), 295 - 295, web_of_science

  • X-ray detection from the distant cluster of galaxies around 3CR184

    T Mihara; K Nogami; M Hattori; K Mitsuda; N Ota

    WILEY-V C H VERLAG GMBH, 1999年, ASTRONOMISCHE NACHRICHTEN, 320 (4-5), 293 - 293, web_of_science

  • 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., SPIE-INT SOC OPTICAL ENGINEERING, 1999年, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY X, 3765, 645 - 663, web_of_science

  • Detection of Iron emission line from the galaxy cluster including the distant radio galaxy 3C220.1

    N Ota; K Mitsuda; M Hattori; T Mihara

    WILEY-V C H VERLAG GMBH, 1999年, ASTRONOMISCHE NACHRICHTEN, 320 (4-5), 295 - 295, web_of_science

  • X-ray detection from the distant cluster of galaxies around 3CR184

    T Mihara; K Nogami; M Hattori; K Mitsuda; N Ota

    WILEY-V C H VERLAG GMBH, 1999年, ASTRONOMISCHE NACHRICHTEN, 320 (4-5), 293 - 293, web_of_science

  • 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., IOP PUBLISHING LTD, 1998年03月, ASTROPHYSICAL JOURNAL, 495 (1), 170 - 178, doi;web_of_science

  • 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., SPIE-INT SOC OPTICAL ENGINEERING, 1998年, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY IX, 3445, 155 - 168, web_of_science

  • 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, American Astronomical Society, 193rd AAS Meeting, Bulletin of the American Astronomical Society, 30, 1374

  • 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., KLUWER ACADEMIC PUBL, 1998年, HOT UNIVERSE, (188), 319 - 320, web_of_science

  • 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., SPIE-INT SOC OPTICAL ENGINEERING, 1998年, EUV, X-RAY, AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY IX, 3445, 155 - 168, web_of_science

  • 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, American Astronomical Society, 193rd AAS Meeting, Bulletin of the American Astronomical Society, 30, 1374

  • 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., KLUWER ACADEMIC PUBL, 1998年, HOT UNIVERSE, (188), 319 - 320, web_of_science

講演・口頭発表等

  • 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

    日本天文学会年会講演予稿集, 2018年08月20日, 2018年08月20日, 2018年08月20日, url

  • XARM status and some prospects

    Preparing the science of galaxy clusters & WHIM with Athena, 2018年

  • X線衛星代替機における科学運用の計画概要

    第18回宇宙科学シンポジウム, 2018年

  • X線天文衛星 Athena の現状

    第18回宇宙科学シンポジウム, 2018年

  • 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

    日本天文学会2018年春季年会, 2018年

  • 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

    日本天文学会2018年春季年会, 2018年

  • HSC による弱重力レンズ効果を利用した銀河団探査

    日本天文学会2018年春季年会, 2018年

  • XMM-Newton 衛星による 5 つの高赤方偏移 HSC 銀河団の観測

    日本天文学会2018年春季年会, 2018年

  • 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)

    日本天文学会2018年春季年会, 2018年

  • X線衛星代替機 XARM における科学運用計画

    日本天文学会2018年春季年会, 2018年

  • 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

    日本天文学会2018年春季年会, 2018年

  • 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)

    日本天文学会2018年春季年会, 2018年

  • XARM status and some prospects

    Preparing the science of galaxy clusters & WHIM with Athena, 2018年

  • 「ひとみ」搭載軟X線帯観測装置の軌道上性能

    第17回宇宙科学シンポジウム, 2017年

  • 「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

    日本天文学会2017年春季年会, 2017年

  • 「すざく」衛星による Abell2163 銀河団外縁部の詳細な解析

    日本天文学会2017年春季年会, 2017年

  • 「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

    日本天文学会2017年春季年会, 2017年

  • 「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

    日本天文学会2017年春季年会, 2017年

  • 「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

    日本天文学会2017年春季年会, 2017年

  • ALMA によるスニヤエフ・ゼルドビッチ効果の初観測

    日本天文学会2017年春季年会, 2017年

  • 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

    日本天文学会2017年春季年会, 2017年

  • 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

    日本物理学会 第72回年次大会, 2017年

  • Constraints on new spectral features and atomic modeling from the Hitomi spectrum of the Perseus cluster

    The X-ray Universe 2017, 2017年

  • Gas motions in the Perseus galaxy cluster observed with Hitomi

    The X-ray Universe 2017, 2017年

  • Suzaku study of the WHIM and future prospects

    Whereabouts and Physics of the Roaming Baryons in the Universe, 2017年

  • X-ray Follow-up Survey in the Hyper Suprime-Cam Subaru Strategic Program Field

    Early Stages of Galaxy Cluster Formation, 2017年

  • 「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

    日本天文学会2017年秋季年会, 2017年

  • 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

    日本天文学会2017年秋季年会, 2017年

  • 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

    日本天文学会2017年秋季年会, 2017年

  • 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

    日本天文学会2017年秋季年会, 2017年

  • 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)

    日本天文学会2017年秋季年会, 2017年

  • 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

    日本天文学会2017年秋季年会, 2017年

  • X線天文衛星 Athena計画

    日本天文学会2017年秋季年会, 2017年

  • Constraints on new spectral features and atomic modeling from the Hitomi spectrum of the Perseus cluster

    The X-ray Universe 2017, 2017年

  • Gas motions in the Perseus galaxy cluster observed with Hitomi

    The X-ray Universe 2017, 2017年

  • Suzaku study of the WHIM and future prospects

    Whereabouts and Physics of the Roaming Baryons in the Universe, 2017年

  • X-ray Follow-up Survey in the Hyper Suprime-Cam Subaru Strategic Program Field

    Early Stages of Galaxy Cluster Formation, 2017年

  • ASTRO-Hの目指すサイエンス

    第16回宇宙科学シンポジウム, 2016年

  • ASTRO-H 衛星搭載 軟X線分光システム SXS

    第16回宇宙科学シンポジウム, 2016年

  • 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

    日本天文学会2016年春季年会, 2016年

  • 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

    日本天文学会2016年春季年会, 2016年

  • ダークバリオン探査ミッションDIOS開発の進展状況

    日本天文学会2016年春季年会, 2016年

  • ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XV

    日本天文学会2016年春季年会, 2016年

  • ASTRO-H搭載 精密軟X線分光装置SXSの現状

    日本物理学会 第71回年次大会, 2016年

  • すざく衛星による銀河団 RXC J1053.7+5453 の温度測定

    日本天文学会2016年秋季年会, 2016年

  • ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XVI

    日本天文学会2016年秋季年会, 2016年

  • すざく衛星による衝突銀河団A2255, A2744の温度構造の研究

    第15回宇宙科学シンポジウム, 2015年

  • 「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

    第15回宇宙科学シンポジウム, 2015年

  • 「すざく」で探す銀河団外縁部のサブハロー/ガス塊

    第15回宇宙科学シンポジウム, 2015年

  • ASTRO-Hの目指すサイエンス

    第15回宇宙科学シンポジウム, 2015年

  • ASTRO-H衛星搭載 SXS-XCS検出器

    第15回宇宙科学シンポジウム, 2015年

  • New Frontiers in Galaxy Clusters with ASTRO-H

    American Astronomical Society, AAS Meeting, 2015年

  • ASTRO-H搭載精密軟X線分光装置SXSの開発の現状 XIII

    日本天文学会2015年春季年会, 2015年

  • Prospects of Cluster Observations with ASTRO-H

    Astroparticle View of Galaxy Clusters, 2015年

  • New Frontiers in Galaxy Clusters with ASTRO-H

    IAU General Assembly, Meeting #29, 2015年

  • Evolution of Groups and Clusters of Galaxies with Athena

    Exploring the Hot and Energetic Universe: The first Scientific Conference dedicated to the Athena X-ray Observatory, 2015年

  • 「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

    日本天文学会2015年秋季年会, 2015年

  • ダークバリオン探査ミッションDIOS開発の進展状況

    日本天文学会2015年秋季年会, 2015年

  • ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XIV

    日本天文学会2015年秋季年会, 2015年

  • New Frontiers in Galaxy Clusters with ASTRO-H

    American Astronomical Society, AAS Meeting, 2015年

  • Prospects of Cluster Observations with ASTRO-H

    Astroparticle View of Galaxy Clusters, 2015年

  • New Frontiers in Galaxy Clusters with ASTRO-H

    IAU General Assembly, Meeting #29, 2015年

  • Evolution of Groups and Clusters of Galaxies with Athena

    Exploring the Hot and Energetic Universe: The first Scientific Conference dedicated to the Athena X-ray Observatory, 2015年

  • ASTRO-H の目指すサイエンス

    第14回宇宙科学シンポジウム, 2014年

  • ASTRO-H 衛星搭載 SXS-XCS 検出器

    第14回宇宙科学シンポジウム, 2014年

  • 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

    第14回宇宙科学シンポジウム, 2014年

  • Exploring gas properties along filaments of the Pandora’s cluster with Suzaku

    Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 2014年

  • Search for gas bulk motions in eight nearby clusters with Suzaku

    Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 2014年

  • Search for very hot/non-thermal emission and gas motions in clusters

    Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 2014年

  • ASTRO-H搭載精密軟X線分光装置SXSの開発の現状XI

    日本天文学会2014年春季年会, 2014年

  • ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 (VI)

    日本物理学会 第69回年次大会, 2014年

  • 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

    日本天文学会2014年秋季年会, 2014年

  • 銀河団外縁部のエントロピー異常の原因の検証

    日本天文学会2014年秋季年会, 2014年

  • ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 XII

    日本天文学会2014年秋季年会, 2014年

  • Exploring gas properties along filaments of the Pandora’s cluster with Suzaku

    Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 2014年

  • Search for gas bulk motions in eight nearby clusters with Suzaku

    Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 2014年

  • Search for very hot/non-thermal emission and gas motions in clusters

    Suzaku-MAXI 2014: Expanding the Frontiers of the X-ray Universe, 2014年

  • ASTRO-H の目指すサイエンス

    第13回宇宙科学シンポジウム, 2013年

  • ASTRO-H 衛星搭載 SXS-XCS 検出器

    第13回宇宙科学シンポジウム, 2013年

  • すざく衛星による近傍銀河団のガスバルク運動の測定

    第13回宇宙科学シンポジウム, 2013年

  • 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

    第13回宇宙科学シンポジウム, 2013年

  • 「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

    第13回宇宙科学シンポジウム, 2013年

  • Galaxy Clusters: Mapping Non-Thermal Pressure & Measuring Mass

    The 8th ASTRO-H Science Meeting, 2013年

  • Density profile of cool core of galaxy clusters

    The mass profiles of galaxy clusters from the core to the outskirts: the need for a multi-wavelength approach, 2013年

  • 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

    日本天文学会2013年春季年会, 2013年

  • 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

    日本天文学会2013年春季年会, 2013年

  • すざく衛星による近傍銀河団のガスバルク運動の探査

    日本天文学会2013年春季年会, 2013年

  • ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(IX)

    日本天文学会2013年春季年会, 2013年

  • Status of ASTRO-H

    The 8th IACHEC meeting, 2013年

  • ASTRO-H搭載 精密軟X線分光装置SXSの開発の現状(V)

    日本物理学会 第68回年次大会, 2013年

  • 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

    日本物理学会 第68回年次大会, 2013年

  • ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(X)

    日本天文学会2013年秋季年会, 2013年

  • 超新星残骸G348.5+0.1のX線放射について

    日本天文学会2013年秋季年会, 2013年

  • Galaxy Clusters: Mapping Non-Thermal Pressure & Measuring Mass

    The 8th ASTRO-H Science Meeting, 2013年

  • Density profile of cool core of galaxy clusters

    The mass profiles of galaxy clusters from the core to the outskirts: the need for a multi-wavelength approach, 2013年

  • Status of ASTRO-H

    The 8th IACHEC meeting, 2013年

  • 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

    第12回宇宙科学シンポジウム, 2012年

  • 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

    第12回宇宙科学シンポジウム, 2012年

  • ASTRO-H の目指すサイエンス 1

    第12回宇宙科学シンポジウム, 2012年

  • ASTRO-H の目指すサイエンス 2

    第12回宇宙科学シンポジウム, 2012年

  • ASTRO-H 衛星搭載 SXS-XCS 検出器

    第12回宇宙科学シンポジウム, 2012年

  • 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

    第12回宇宙科学シンポジウム, 2012年

  • ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(VII)

    日本天文学会2012年春季年会, 2012年

  • すざく衛星を用いたThe Bullet Clusterの硬X線探査

    日本天文学会2012年春季年会, 2012年

  • 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

    日本天文学会2012年春季年会, 2012年

  • 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

    日本天文学会2012年春季年会, 2012年

  • 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

    日本天文学会2012年春季年会, 2012年

  • 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

    日本天文学会2012年春季年会, 2012年

  • 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

    日本天文学会2012年春季年会, 2012年

  • 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

    日本天文学会2012年春季年会, 2012年

  • 「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

    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」, 2012年

  • Impact of Suzaku Measurements on Astroparticle Physics

    Vulcano Workshop 2012: Frontier Objects in Astrophysics and Particle Physics, 2012年

  • Cluster large-scale dynamics

    The 8th ASTRO-H Science Meeting, 2012年

  • The ASTRO-H Mission

    Science with eROSITA and ART-XC aboard Spectrum-RG, 2012年

  • ASTRO-H搭載精密軟X線分光装置SXSの開発の現状(VIII)

    日本天文学会2012年秋季年会, 2012年

  • 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

    日本天文学会2012年秋季年会, 2012年

  • 「すざく」衛星によるAbell 478銀河団の外縁部の観測

    日本天文学会2012年秋季年会, 2012年

  • Impact of Suzaku Measurements on Astroparticle Physics

    Vulcano Workshop 2012: Frontier Objects in Astrophysics and Particle Physics, 2012年

  • Cluster large-scale dynamics

    The 8th ASTRO-H Science Meeting, 2012年

  • The ASTRO-H Mission

    Science with eROSITA and ART-XC aboard Spectrum-RG, 2012年

  • Detection of hard X-ray emission from the hottest Abell galaxy cluster A2163 with Suzaku

    Exploring the X-ray Universe: Suzaku and Beyond, 2011年

  • 「すざく」衛星によるAbell 1835銀河団の外縁部の研究

    日本天文学会2011年秋季年会, 2011年

  • 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

    日本天文学会2011年秋季年会, 2011年

  • ASTRO-H 搭載 精密軟 X 線分光装置 SXS の開発の現状 (VI)

    日本天文学会2011年秋季年会, 2011年

  • Detection of hard X-ray emission from the hottest Abell galaxy cluster A2163 with Suzaku

    Exploring the X-ray Universe: Suzaku and Beyond, 2011年

  • Clusters of galaxies seen in X-rays: current status and prospects

    Naomi Ota

    NECO workshop: Probing the Extragalactic Universe with High Energy and Very High Energy Sources, 2020年12月09日, 2020年12月09日, 2020年12月09日

    口頭発表(招待・特別)

  • ASCA observations of the lensing clusters CL 0500-24, CL 2244-02, and A370: Mass determinations and comparisons

    N Ota; K Mitsuda; Y Fukazawa

    ASTROPHYSICAL JOURNAL, 1998年03月, 1998年03月, 1998年03月, 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., doi

  • X線天文衛星Athena計画

    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, 2017年08月20日, 2017年08月20日, 2017年08月20日, url

  • 「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

    日本天文学会年会講演予稿集, 2017年02月28日, 2017年02月28日, 2017年02月28日, url

  • 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)

    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

    日本天文学会2021年春期年会, 2021年03月16日, 2021年03月18日, 2021年03月18日

  • 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)

    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

    日本天文学会2021年春期年会, 2021年03月18日, 2021年03月16日, 2021年03月16日

  • 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

    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

    日本天文学会2021年春期年会, 2021年03月17日, 2021年03月16日, 2021年03月16日

  • ダークバリオン探査衛星: Super DIOS

    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

    第21回宇宙科学シンポジウム, 2021年01月06日, 2021年01月06日, 2021年01月06日

  • 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

    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

    日本天文学会2020年秋期年会, 2020年09月10日, 2020年09月08日, 2020年09月08日

    口頭発表(一般)

  • 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)

    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

    日本天文学会2020年秋期年会, 2020年09月10日, 2020年09月08日, 2020年09月08日

  • 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)

    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

    日本天文学会2020年秋期年会, 2020年09月10日, 2020年09月08日, 2020年09月08日

  • 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

    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

    日本天文学会2020年秋期年会, 2020年09月08日, 2020年09月08日, 2020年09月08日

  • X 線天文衛星Athena計画の現状

    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

    日本天文学会2020年秋期年会, 2020年09月08日, 2020年09月08日, 2020年09月08日

  • 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)

    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, 2020年03月19日, 2020年03月16日, 2020年03月16日

  • 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

    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, 2020年03月18日, 2020年03月16日, 2020年03月16日

  • 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

    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, 2020年03月16日, 2020年03月16日, 2020年03月16日

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, rm:research_project_id


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