宇宙物理学研究系

藤本 龍一

フジモト リュウイチ  (Ryuichi Fujimoto)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙物理学研究系 教授
総合研究大学院大学 先端学術院 宇宙科学コース 教授
東京工業大学 理学院 特定教授
学位
博士(理学)(東京大学)
修士(東京大学)

研究者番号
20280555
ORCID ID
 https://orcid.org/0000-0002-2374-7073
J-GLOBAL ID
200901095989600566
researchmap会員ID
1000363020

X線マイクロカロリメータを用いた極低温精密X線分光装置の開発に取り組み,2023年9月打ち上げのXRISM衛星に搭載されたResolve観測装置として実現しました.

研究指導のテーマとしては,(1) XRISM衛星による精密X線分光観測データを解析し,銀河団ガスの運動を調べて,宇宙の大規模構造形成過程の理解を深める,(2) 宇宙マイクロ波背景放射の偏光観測を目指すLiteBIRD衛星を見据えた実験的研究を行なう等.特定の自然現象について理解を深めると同時に,複雑な自然現象の背景にある物理法則に至る過程を,実験・解析手法とともにしっかりと身につけてもらいたいと考えています.


学歴

 4

委員歴

 2

論文

 163
  • Marc Audard, Hisamitsu Awaki, Ralf Ballhausen, Aya Bamba, Ehud Behar, Rozenn Boissay-Malaquin, Laura Brenneman, Gregory V. Brown, Lia Corrales, Elisa Costantini, Renata Cumbee, Maria Diaz Trigo, Chris Done, Tadayasu Dotani, Ken Ebisawa, Megan E. Eckart, Dominique Eckert, Teruaki Enoto, Satoshi Eguchi, Yuichiro Ezoe, Adam Foster, Ryuichi Fujimoto, Yutaka Fujita, Yasushi Fukazawa, Kotaro Fukushima, Akihiro Furuzawa, Luigi Gallo, Javier A. García, Liyi Gu, Matteo Guainazzi, Kouichi Hagino, Kenji Hamaguchi, Isamu Hatsukade, Katsuhiro Hayashi, Takayuki Hayashi, Natalie Hell, Edmund Hodges-Kluck, Ann Hornschemeier, Yuto Ichinohe, Manabu Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Jelle Kaastra, Timothy Kallman, Erin Kara, Satoru Katsuda, Yoshiaki Kanemaru, Richard Kelley, Caroline Kilbourne, Shunji Kitamoto, Shogo Kobayashi, Takayoshi Kohmura, Aya Kubota, Maurice Leutenegger, Michael Loewenstein, Yoshitomo Maeda, Maxim Markevitch, Hironori Matsumoto, Kyoko Matsushita, Dan McCammon, Brian McNamara, François Mernier, Eric D. Miller, Jon M. Miller, Ikuyuki Mitsuishi, Misaki Mizumoto, Tsunefumi Mizuno, Koji Mori, Koji Mukai, Hiroshi Murakami, Richard Mushotzky, Hiroshi Nakajima, Kazuhiro Nakazawa, Jan-Uwe Ness, Kumiko Nobukawa, Masayoshi Nobukawa, Hirofumi Noda, Hirokazu Odaka, Shoji Ogawa, Anna Ogorzalek, Takashi Okajima, Naomi Ota, Stephane Paltani, Robert Petre, Paul Plucinsky, Frederick S. Porter, Katja Pottschmidt, Kosuke Sato, Toshiki Sato, Makoto Sawada, Hiromi Seta, Megumi Shidatsu, Aurora Simionescu, Randall Smith, Hiromasa Suzuki, Andrew Szymkowiak, Hiromitsu Takahashi, Mai Takeo, Toru Tamagawa, Keisuke Tamura, Takaaki Tanaka, Atsushi Tanimoto, Makoto Tashiro, Yukikatsu Terada, Yuichi Terashima, Yohko Tsuboi, Masahiro Tsujimoto, Hiroshi Tsunemi, Takeshi Tsuru, Hiroyuki Uchida, Nagomi Uchida, Yuusuke Uchida, Hideki Uchiyama, Yoshihiro Ueda, Shinichiro Uno, Jacco Vink, Shin Watanabe, Brian J. Williams, Satoshi Yamada, Shinya Yamada, Hiroya Yamaguchi, Kazutaka Yamaoka, Noriko Yamasaki, Makoto Yamauchi, Shigeo Yamauchi, Tahir Yaqoob, Tomokage Yoneyama, Tessei Yoshida, Mihoko Yukita, Irina Zhuravleva, Xin Xiang, Takeo Minezaki, Margaret Buhariwalla, Dimitra Gerolymatou, Scott Hagen
    The Astrophysical Journal Letters 973(1) L25-L25 2024年9月1日  
    Abstract We present an analysis of the first two XRISM/Resolve spectra of the well-known Seyfert-1.5 active galactic nucleus (AGN) in NGC 4151, obtained in 2023 December. Our work focuses on the nature of the narrow Fe K α emission line at 6.4 keV, the strongest and most common X-ray line observed in AGN. The total line is found to consist of three components. Even the narrowest component of the line is resolved with evident Fe K α,1 (6.404 keV) and K α,2 (6.391 keV) contributions in a 2:1 flux ratio, fully consistent with neutral gas with negligible bulk velocity. Subject to the limitations of our models, the narrowest and intermediate-width components are consistent with emission from optically thin gas, suggesting that they arise in a disk atmosphere and/or wind. Modeling the three line components in terms of Keplerian broadening, they are readily associated with (1) the inner wall of the “torus,” (2) the innermost optical “broad-line region” (or “X-ray BLR”), and (3) a region with a radius of r ≃ 100 GM/c 2 that may signal a warp in the accretion disk. Viable alternative explanations of the broadest component include a fast-wind component and/or scattering; however, we find evidence of variability in the narrow Fe K α line complex on timescales consistent with small radii. The best-fit models are statistically superior to simple Voigt functions, but when fit with Voigt profiles the time-averaged lines are consistent with a projected velocity broadening of FWHM . Overall, the resolution and sensitivity of XRISM show that the narrow Fe K line in AGN is an effective probe of all key parts of the accretion flow, as it is currently understood. We discuss the implications of these findings for our understanding of AGN accretion, future studies with XRISM, and X-ray-based black hole mass measurements.
  • Yoshitomo Maeda, Ryuichi Fujimoto, Hisamitsu Awaki, Jesus C. Balleza, Kim R. Barnstable, Thomas G. Bialas, Rozenn Boissay-Malaquin, Gregory V. Brown, Edgar R. Canavan, Timothy M. Carnahan, Meng P. Chiao, Brian J. Comber, Elisa Costantini, Renata S. Cumbee, Jan-Willem A. den Herder, Johannes Dercksen, Cor P. de Vries, Michael J. DiPirro, Megan E. Eckart, Yuichiro Ezoe, Carlo Ferrigno, Nathalie Q. S. Gorter, Steven M. Graham, Martin Grim, Leslie S. Hartz, Ryota Hayakawa, Takayuki Hayashi, Natalie Hell, Akio Hoshino, Yuto Ichinohe, Daiki Ishi, Manabu Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Bryan L. James, Yoshiaki Kanemaru, Richard L. Kelley, Steven J. Kenyon, Caroline A. Kilbourne, Mark O. Kimball, Shunji Kitamoto, Maurice A. Leutenegger, Dan McCammon, Brian J. McLaughlin, Joseph J. Miko, Erik van der Meer, Misaki Mizumoto, Takashi Okajima, Atsushi Okamoto, Stéphane Paltani, Frederick S. Porter, Lillian S. Reichenthal, Kosuke Sato, Toshiki Sato, Yohichi Sato, Makoto Sawada, Keisuke Shinozaki, Russell F. Shipman, Peter J. Shirron, Gary A. Sneiderman, Soong Yang, Richard Szymkiewicz, Andrew E. Szymkowiak, Yoh Takei, Mai Takeo, Tsubasa Tamba, Keisuke Tamura, Masahiro Tsujimoto, Yuusuke Uchida, Stephen Wasserzug, Michael C. Witthoeft, Rob Wolfs, Shinya Yamada, Susumu Yasuda
    Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 53-53 2024年8月22日  
  • Richard L. Kelley, Hisamitsu Awaki, Jesus C. Balleza, Kim R. Barnstable, Thomas G. Bialas, Rozenn Boissay-Malaquin, Gregory V. Brown, Edgar R. Canavan, Timothy M. Carnahan, Meng P. Chiao, Brian J. Comber, Elisa Costantini, Renata S. Cumbee, Jan-Willem A. den Herder, Johannes Dercksen, Cor de Vries, Michael J. DiPirro, Megan E. Eckart, Yuichiro Ezoe, Carlo Ferrigno, Ryuichi Fujimoto, Nathalie Q. S. Gorter, Steven M. Graham, Martin Grim, Leslie S. Hartz, Ryota Hayakawa, Takayuki Hayashi, Natalie Hell, Akio Hoshino, Yuto Ichinohe, Daiki Ishi, Manabu Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Bryan L. James, Yoshiaki Kanemaru, Steven J. Kenyon, Caroline A. Kilbourne, Mark O. Kimball, Shunji Kitamoto, Maurice A. Leutenegger, Yoshitomo Maeda, Dan McCammon, Brian J. McLaughlin, Joseph J. Miko, Erik van der Meer, Misaki Mizumoto, Takashi Okajima, Atsushi Okamoto, Stéphane Paltani, Frederick S. Porter, Lillian S. Reichenthal, Kosuke Sato, Toshiki Sato, Yohichi Sato, Makoto Sawada, Keisuke Shinozaki, Russell F. Shipman, Peter J. Shirron, Gary A. Sneiderman, Soong Yang, Richard Szymkiewicz, Andrew E. Szymkowiak, Yoh Takei, Mai Takeo, Tsubasa Tamba, Keisuke Tamura, Masahiro Tsujimoto, Yuusuke Uchida, Stephen Wasserzug, Michael C. Witthoeft, Rob Wolfs, Shinya Yamada, Susumu Yasuda
    Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 55-55 2024年8月22日  
  • Makoto S. Tashiro, Shin Watanabe, Hironori Maejima, Kenichi Toda, Kyoko Matsushita, Hiroya Yamaguchi, Richard L. Kelley, Lillian S. Reichenthal, Leslie S. Hartz, Robert Petre, Brian J. Williams, Matteo Guainazzi, Andrea Santovincenzo, Elisa Costantini, Yoh Takei, Yoshitaka Ishisaki, Ryuichi Fujimoto, Joy Henegar-Leon, Gary Sneiderman, Hiroshi Tomida, Koji Mori, Hiroshi Nakajima, Yukikatsu Terada, Matt Holland, Micheal Loewenstein, Tomothey Kallman, Jelle Kaastra, Eric Miller, Makoto Sawada, Chris Done, Teruaki Enoto, Aya Bamba, Paul Plucinsky, Yoshitaka Ueda, Erin Kara, Irina Zhuravleva, Yutaka Fujita, Jose Antonio Quero, Yoshitaka Arai, Marc Audard, Hisamitsu Awaki, Chris Baluta, Nobutaka Bando, Ehud Behar, Thomas Bialas, Rozenn Boissay-Malaquin, Laura Brenneman, Gregory V. Brown, Meng Chiao, Lia Corrales, Renata Cumbee, Cor de Vries, Jan-Willem den Herder, Maria Diaz-Trigo, Michael DiPirro, Tadayasu Dotani, Jacobo Ebrero Carrero, Ken Ebisawa, Megan Eckart, Dominique Eckart, Satoshi Eguchi, Yuichiro Ezoe, Carlo Ferrgno, Adam Foster, Yasushi Fukazawa, Kotaro Fukushima, Akihiro Furuzawa, Luigi Gallo, Nathalie Gorter, Martin Grim, Liyi Gu, Koichi Hagino, Kenji Hamaguchi, Isamu Hatsukade, Katsuhiro Hayashi, Takayuki Hayashi, Natalie Hell, Edmund Hodges-Kluck, Takafumi Horiuchi, Ann Hornschemeier, Akio Hoshino, Yuto Ichinohe, Chisato Ikuta, Ryo Iizuka, Daiki Ishi, Manabu Ishida, Naoki Ishihama, Kumi Ishikawa, Kosei Ishimura, Tess Jaffe, Satoru Katsuda, Yoshiaki Kanemaru, Steven Kenyon, Caroline Kilbourne, Mark Kimball, Shunji Kitamoto, Shogo Kobayashi, Akihide Kobayashi, Takayoshi Kohmura, Aya Kubota, Maurice Leutenegger, Muzi Li, Yoshitomo Maeda, Maxim Markevitch, Hironori Matsumoto, Keiichi Matsuzaki, Dan McCammon, Brian McLaughlin, Brian McNamara, Josegh Miko, Jon Miller, Kenji Minesugi, Shinji Mitani, Ikuyuki Mitsuishi, Misaki Mizumoto, Tsunefumi Mizuno, Koji Mukai, Hiroshi Murakami, Richard Mushotzky, Kazuhiro Nakazawa, Chikara Natsukari, Jan-Uwe Ness, Kenichiro Nigo, Mari Nishiyama, Kumiko Nobukawa, Masayoshi Nobukawa, Hirofumi Noda, Hirokazu Odaka, Mina Ogawa, Shoji Ogawa, Takashi Okajima, Atsushi Okamoto, Naomi Ota, Masanobu Ozaki, Stephane Paltani, F. Scott Porter, Katja Pottschmidt, Takahiro Sasaki, Kosuke Sato, Rie Sato, Toshiki Sato, Yoichi Sato, Hiromi Seta, Maki Shida, Megumi Shidatsu, Shuhei Shigeto, Russel Shipman, Keisuke Shinozaki, Peter Shirron, Aurora Simionescu, Randall Smith, Young Soong, Hiromasa Suzuki, Andy Szymkowiak, Hiromitsu Takahashi, Mai Takeo, Toru Tamagawa, Keisuke Tamura, Takaaki Tanaka, Atsushi Tanimoto, Yoichi Terashima, Yohko Tsuboi, Masahiro Tsujimoto, Hiroshi Tsunemi, Takeshi Tsuru, Hiroyuki Uchida, Nagomi Ucghida, Yuusuke Uchida, Hideki Uchiyama, Shinichiro Uno, Erik Van der Meer, Jacco Vink, Michael Wittheof, Rob Wolf, Satoshi Yamada, Shinya Yamada, Kazutaka Yamaoka, Noriko Yamasaki, Makoto Yamauchi, Shigeo Yamauchi, Keiichi Yamagase, Tahir Yaqoob, Susumu Yasuda, Tomokage Yoneyama, Tessei Yoshida
    Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 52-52 2024年8月21日  
  • Kosuke Sato, Yoshitaka Ishisaki, Richard L. Kelley, Hisamitsu Awaki, Jesus C. Balleza, Kim R. Barnstable, Thomas G. Bialas, Rozenn Boissay-Malaquin, Gregory V. Brown, Edgar R. Canavan, Renata S. Cumbee, Timothy M. Carnahan, Meng P. Chiao, Brian J. Comber, Elisa Costantini, Jan-Willem A. den Herder, Johannes Dercksen, Cor de Vries, Michael J. DiPirro, Megan E. Eckart, Yuichiro Ezoe, Carlo Ferrigno, Ryuichi Fujimoto, Nathalie Q. S. Gorter, Steven M. Graham, Martin Grim, Leslie S. Hartz, Ryota Hayakawa, Takayuki Hayashi, Natalie Hell, Akio Hoshino, Yuto Ichinohe, Daiki Ishi, Manabu Ishida, Kumi Ishikawa, Bryan L. James, Yoshiaki Kanemaru, Steven J. Kenyon, Caroline A. Kilbourne, Mark O. Kimball, Shunji Kitamoto, Maurice A. Leutenegger, Yoshitomo Maeda, Dan McCammon, Brian J. McLaughlin, Joseph J. Miko, Erik van der Meer, Misaki Mizumoto, Takashi Okajima, Atsushi Okamoto, Stéphane Paltani, Frederick S. Porter, Lillian S. Reichenthal, Toshiki Sato, Yohichi Sato, Makoto Sawada, Keisuke Shinozaki, Russell F. Shipman, Peter J. Shirron, Gary A. Sneiderman, Soong Yang, Richard Szymkiewicz, Andrew E. Szymkowiak, Yoh Takei, Mai Takeo, Tsubasa Tamba, Keisuke Tamura, Masahiro Tsujimoto, Yuusuke Uchida, Stephen Wasserzug, Michael C. Witthoeft, Rob Wolfs, Shinya Yamada, Susumu Yasuda, Seiji Yoshida
    Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 232-232 2024年8月21日  

MISC

 131
  • 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 225 2018年8月20日  
  • 江副祐一郎, 石崎欣尚, 藤本龍一, 竹井洋, 石川久美, 安田進, 柳瀬慶一, 山崎典子, 佐藤浩介, 北本俊二, 小山志勇, 野田博文, 吉田誠至, 金尾憲一, 恒松正二, KELLEY R. L., KILBOURNE C. A., DIPIRRO M. J., SHIRRON P.
    日本天文学会年会講演予稿集 2018 2018年  
  • Alle, S.W., Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S.W., Angelini, L., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M.W., Blandford, R., Brenneman, L.W., Brown, G.V., Bulbul, E., Cackett, E.M., Chernyakova, M., Chiao, M.P., Coppi, P.S., Costantini, E., De Plaa, J., De Vries, C.P., Den Herder, J.-W., Done, C., Dotani, T., Ebisawa, K., Eckart, M.E., Enoto, T., Ezoe, Y., Fabian, A.C., Ferrigno, C., Foster, A.R., Fujimoto, R., Fukazawa, Y., Furuzawa, A., Galeazzi, M., Gallo, L.C., Gandhi, P., Giustini, M., Goldwurm, A., Gu, L., Guainazzi, M., Haba, Y., Hagino, K., Hamaguchi, K., Harrus, I.M., Hatsukade, I., Hayashi, K., Hayashi, T., Hayashida, K., Hiraga, J.S., Hornschemeier, A., Hoshino, A., Hughes, J.P., Ichinohe, Y., Iizuka, R., Inoue, H., Inoue, Y., Ishida, M., Ishikawa, K., Ishisaki, Y., Iwai, M., Kaastra, J., Kallman, T., Kamae, T., Kataoka, J., Katsuda, S., Kawai, N., Kelley, R.L., Kilbourne, C.A., Kitaguchi, T., Kitamoto, S., Kitayama, T., Kohmura, T., Kokubun, M., Koyama, K., Koyama, S., Kretschmar, P., Krimm, H.A., Kubota, A., Kunieda, H., Laurent, P., Lee, S.-H., Leutenegger, M.A., Limousin, O.O., Loewenstein, M., Long, K.S., Lumb, D., Madejski, G., Maeda, Y., Maier, D., Makishima, K., Markevitch, M., Matsumoto, H., Matsushita, K., Mccammon, D., Mcnamara, B.R., Mehdipour, M., Miller, E.D., Miller, J.M., Mineshige, S., Mitsuda, K., Mitsuishi, I., Miyazawa, T., Mizuno, T., Mori, H., Mori, K., Mukai, K., Murakami, H., Mushotzky, R.F., Nakagawa, T., Nakajima, H., Nakamori, T., Nakashima, S., Nakazawa, K., Nobukawa, K.K., Nobukawa, M., Noda, H., Odaka, H., Ohashi, T., Ohno, M., Okajima, T., Ota, N., Ozaki, M., Paerels, F., Paltani, S., Petre, R., Pinto, C., Porter, F.S., Pottschmidt, K., Reynolds, C.S., Safi-Harb, S., Saito, S., Sakai, K., Sasaki, T., Sato, G., Sato, K., Sato, R., Sawada, M., Schartel, N., Serlemtsos, P.J., Seta, H., Shidatsu, M., Simionescu, A., Smith, R.K., Soong, Y., Stawarz, Ł., Sugawara, Y., Sugita, S., Szymkowiak, A., Tajima, H., Takahashi, H., Takahashi, T., Takeda, S., Takei, Y., Tamagawa, T., Tamura, T., Tanaka, T., Tanaka, Y., Tanaka, Y.T., Tashiro, M.S., Tawara, Y., Terada, Y., Terashima, Y., Tombesi, F., Tomida, H., Tsuboi, Y., Tsujimoto, M., Tsunemi, H., Suru, T.G., Uchida, H., Uchiyama, H., Uchiyama, Y., Ueda, S., Ueda, Y., Uno, S., Urry, C.M., Ursino, E., Watanabe, S., Werner, N., Wilkins, D.R., Williams, B.J., Yamada, S., Yamaguchi, H., Yamaoka, K., Yamasaki, N.Y., Yamauchi, M., Yamauchi, S., Yaqoob, T., Yatsu, Y., Yonetoku, D., Zhuravleva, I., Zoghbi, A., Nakaniwa, N.
    Publications of the Astronomical Society of Japan 70(2) 2018年  
    We report a Hitomi observation of IGR J16318-4848, a high-mass X-ray binary<br /> system with an extremely strong absorption of N_H~10^{24} cm^{-2}. Previous<br /> X-ray studies revealed that its spectrum is dominated by strong fluorescence<br /> lines of Fe as well as continuum emission. For physical and geometrical insight<br /> into the nature of the reprocessing material, we utilize the high spectroscopic<br /> resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer;<br /> SXS) and the wide-band sensitivity by the soft and hard X-ray imager (SXI and<br /> HXI) aboard Hitomi. Even though photon counts are limited due to unintended<br /> off-axis pointing, the SXS spectrum resolves Fe K{\alpha_1} and K{\alpha_2}<br /> lines and puts strong constraints on the line centroid and width. The line<br /> width corresponds to the velocity of 160^{+300}_{-70} km s^{-1}. This<br /> represents the most accurate, and smallest, width measurement of this line made<br /> so far from any X-ray binary, much less than the Doppler broadening and shift<br /> expected from speeds which are characteristic of similar systems. Combined with<br /> the K-shell edge energy measured by the SXI and HXI spectra, the ionization<br /> state of Fe is estimated to be in the range of Fe I--IV. Considering the<br /> estimated ionization parameter and the distance between the X-ray source and<br /> the absorber, the density and thickness of the materials are estimated. The<br /> extraordinarily strong absorption and the absence of a Compton shoulder<br /> component is confirmed. These characteristics suggest reprocessing materials<br /> which are distributed in a narrow solid angle or scattering primarily with warm<br /> free electrons or neutral hydrogen.
  • Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S.W., Angelini, L., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M.W., Blandford, R., Brenneman, L.W., Brown, G.V., Bulbul, E., Cackett, E.M., Chernyakova, M., Chiao, M.P., Coppi, P.S., Costantini, E., De Plaa, J., De Vries, C.P., Den Herder, J.-W., Done, C., Dotani, T., Ebisawa, K., Eckart, M.E., Enoto, T., Ezoe, Y., Fabian, A.C., Ferrigno, C., Foster, A.R., Fujimoto, R., Fukazawa, Y., Furuzawa, A., Galeazzi, M., Gallo, L.C., Gandhi, P., Giustini, M., Goldwurm, A., Gu, L., Guainazzi, M., Haba, Y., Hagino, K., Hamaguchi, K., Harrus, I.M., Hatsukade, I., Hayashi, K., Hayashi, T., Hayashida, K., Hiraga, J.S., Hornschemeier, A., Hoshino, A., Hughes, J.P., Ichinohe, Y., Iizuka, R., Inoue, H., Inoue, Y., Ishida, M., Ishikawa, K., Ishisaki, Y., Iwai, M., Kaastra, J., Kallman, T., Kamae, T., Kataoka, J., Katsuda, S., Kawai, N., Kelley, R.L., Kilbourne, C.A., Kitaguchi, T., Kitamoto, S., Kitayama, T., Kohmura, T., Kokubun, M., Koyama, K., Koyama, S., Kretschmar, P., Krimm, H.A., Kubota, A., Kunieda, H., Laurent, P., Lee, S.-H., Leutenegger, M.A., Limousin, O., Loewenstein, M., Long, K.S., Lumb, D., Madejski, G., Maeda, Y., Maier, D., Makishima, K., Markevitch, M., Matsumoto, H., Matsushita, K., McCammon, D., McNamara, B.R., Mehdipour, M., Miller, E.D., Miller, J.M., Mineshige, S., Mitsuda, K., Mitsuishi, I., Miyazawa, T., Mizuno, T., Mori, H., Mori, K., Mukai, K., Murakami, H., Mushotzky, R.F., Nakagawa, T., Nakajima, H., Nakamori, T., Nakashima, S., Nakazawa, K., Nobukawa, K.K., Nobukawa, M., Noda, H., Odaka, H., Ohashi, T., Ohno, M., Okajima, T., Ota, N., Ozaki, M., Paerels, F., Paltani, S., Petre, R., Pinto, C., Porter, F.S., Pottschmidt, K., Reynolds, C.S., Safi-Harb, S., Saito, S., Sakai, K., Sasaki, T., Sato, G., Sato, K., Sato, R., Sawada, M., Schartel, N., Serlemtsos, P.J., Seta, H., Shidatsu, M., Simionescu, A., Smith, R.K., Soong, Y., Stawarz, L., Sugawara, Y., Sugita, S., Szymkowiak, A., Tajima, H., Takahashi, H., Takahashi, T., Takeda, S., Takei, Y., Tamagawa, T., Tamura, T., Tanaka, T., Tanaka, Y., Tanaka, Y.T., Tashiro, M.S., Tawara, Y., Terada, Y., Terashima, Y., Tombesi, F., Tomida, H., Tsuboi, Y., Tsujimoto, M., Tsunemi, H., Tsuru, T.G., Uchida, H., Uchiyama, H., Uchiyama, Y., Ueda, S., Ueda, Y., Uno, S., Urry, C.M., Ursino, E., Watanabe, S., Werner, N., Wilkins, D.R., Williams, B.J., Yamada, S., Yamaguchi, H., Yamaoka, K., Yamasaki, N.Y., Yamauchi, M., Yamauchi, S., Yaqoob, T., Yatsu, Y., Yonetoku, D., Zhuravleva, I., Zoghbi, A., Uchida, Y.
    Publications of the Astronomical Society of Japan 70(6) 2018年  
    We present the results from the Hitomi Soft Gamma-ray Detector (SGD)<br /> observation of the Crab nebula. The main part of SGD is a Compton camera, which<br /> in addition to being a spectrometer, is capable of measuring polarization of<br /> gamma-ray photons. The Crab nebula is one of the brightest X-ray / gamma-ray<br /> sources on the sky, and, the only source from which polarized X-ray photons<br /> have been detected. SGD observed the Crab nebula during the initial test<br /> observation phase of Hitomi. We performed the data analysis of the SGD<br /> observation, the SGD background estimation and the SGD Monte Carlo simulations,<br /> and, successfully detected polarized gamma-ray emission from the Crab nebula<br /> with only about 5 ks exposure time. The obtained polarization fraction of the<br /> phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1<br /> $\pm$ 10.6)% and, the polarization angle is 110.7$^o$ + 13.2 / $-$13.0$^o$ in<br /> the energy range of 60--160 keV (The errors correspond to the 1 sigma<br /> deviation). The confidence level of the polarization detection was 99.3%. The<br /> polarization angle measured by SGD is about one sigma deviation with the<br /> projected spin axis of the pulsar, 124.0$^o$ $\pm$0.1$^o$.
  • Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S.W., Angelini, L., Audard, M., Awaki, H., Axelsson, M., Bamba, A., Bautz, M.W., Blandford, R., Brenneman, L.W., Brown, G.V., Bulbul, E., Cackett, E.M., Chernyakova, M., Chiao, M.P., Coppi, P.S., Costantini, E., De Plaa, J., De Vries, C.P., Den Herder, J.-W., Done, C., Dotani, T., Ebisawa, K., Eckart, M.E., Enoto, T., Ezoe, Y., Fabian, A.C., Ferrigno, C., Foster, A.R., Fujimoto, R., Fukazawa, Y., Furukawa, M., Furuzawa, A., Galeazzi, M., Gallo, L.C., Gandhi, P., Giustini, M., Goldwurm, A., Gu, L., Guainazzi, M., Haba, Y., Hagino, K., Hamaguchi, K., Harrus, I.M., Hatsukade, I., Hayashi, K., Hayashi, T., Hayashida, K., Hiraga, J.S., Hornschemeier, A., Hoshino, A., Hughes, J.P., Ichinohe, Y., Iizuka, R., Inoue, H., Inoue, Y., Ishida, M., Ishikawa, K., Ishisaki, Y., Iwai, M., Kaastra, J., Kallman, T., Kamae, T., Kataoka, J., Kato, Y., Katsuda, S., Kawai, N., Kelley, R.L., Kilbourne, C.A., Kitaguchi, T., Kitamoto, S., Kitayama, T., Kohmura, T., Kokubun, M., Koyama, K., Koyama, S., Kretschmar, P., Krimm, H.A., Kubota, A., Kunieda, H., Laurent, P., Lee, S.-H., Leutenegger, M.A., Limousin, O., Loewenstein, M., Long, K.S., Lumb, D., Madejski, G., Maeda, Y., Maier, D., Makishima, K., Markevitch, M., Matsumoto, H., Matsushita, K., McCammon, D., McNamara, B.R., Mehdipour, M., Miller, E.D., Miller, J.M., Mineshige, S., Mitsuda, K., Mitsuishi, I., Miyazawa, T., Mizuno, T., Mori, H., Mori, K., Mukai, K., Murakami, H., Mushotzky, R.F., Nakagawa, T., Nakajima, H., Nakamori, T., Nakashima, S., Nakazawa, K., Nobukawa, K.K., Nobukawa, M., Noda, H., Odaka, H., Ohashi, T., Ohno, M., Okajima, T., Ota, N., Ozaki, M., Paerels, F., Paltani, S., Petre, R., Pinto, C., Porter, F.S., Pottschmidt, K., Reynolds, C.S., Safi-Harb, S., Saito, S., Sakai, K., Sasaki, T., Sato, G., Sato, K., Sato, R., Sawada, M., Schartel, N., Serlemtsos, P.J., Seta, H., Shidatsu, M., Simionescu, A., Smith, R.K., Soong, Y., Stawarz, Ł., Sugawara, Y., Sugita, S., Szymkowiak, A., Tajima, H., Takahashi, H., Takahashi, T., Takeda, S., Takei, Y., Tamagawa, T., Tamura, T., Tanaka, T., Tanaka, Y., Tanaka, Y.T., Tashiro, M.S., Tawara, Y., Terada, Y., Terashima, Y., Tombesi, F., Tomida, H., Tsuboi, Y., Tsujimoto, M., Tsunemi, H., Tsuru, T.G., Uchida, H., Uchiyama, H., Uchiyama, Y., Ueda, S., Ueda, Y., Uno, S., Urry, C.M., Ursino, E., Watanabe, S., Werner, N., Wilkins, D.R., Williams, B.J., Yamada, S., Yamaguchi, H., Yamaoka, K., Yamasaki, N.Y., Yamauchi, M., Yamauchi, S., Yaqoob, T., Yatsu, Y., Yonetoku, D., Zhuravleva, I., Zoghbi, A.
    Publications of the Astronomical Society of Japan 70(2) 2018年  
    The present paper investigates the temperature structure of the X-ray<br /> emitting plasma in the core of the Perseus cluster using the 1.8--20.0 keV data<br /> obtained with the Soft X-ray Spectrometer (SXS) onboard the Hitomi Observatory.<br /> A series of four observations were carried out, with a total effective exposure<br /> time of 338 ks and covering a central region $\sim7&#039;$ in diameter. The SXS was<br /> operated with an energy resolution of $\sim$5 eV (full width at half maximum)<br /> at 5.9 keV. Not only fine structures of K-shell lines in He-like ions but also<br /> transitions from higher principal quantum numbers are clearly resolved from Si<br /> through Fe. This enables us to perform temperature diagnostics using the line<br /> ratios of Si, S, Ar, Ca, and Fe, and to provide the first direct measurement of<br /> the excitation temperature and ionization temperature in the Perseus cluster.<br /> The observed spectrum is roughly reproduced by a single temperature thermal<br /> plasma model in collisional ionization equilibrium, but detailed line ratio<br /> diagnostics reveal slight deviations from this approximation. In particular,<br /> the data exhibit an apparent trend of increasing ionization temperature with<br /> increasing atomic mass, as well as small differences between the ionization and<br /> excitation temperatures for Fe, the only element for which both temperatures<br /> can be measured. The best-fit two-temperature models suggest a combination of 3<br /> and 5 keV gas, which is consistent with the idea that the observed small<br /> deviations from a single temperature approximation are due to the effects of<br /> projection of the known radial temperature gradient in the cluster core along<br /> the line of sight. Comparison with the Chandra/ACIS and the XMM-Newton/RGS<br /> results on the other hand suggests that additional lower-temperature components<br /> are present in the ICM but not detectable by Hitomi SXS given its 1.8--20 keV<br /> energy band.

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