用Hitomi观测的Perseus星系团核心温度结构
高能天体物理现象
2018-04-25 v1
摘要
本文利用Hitomi天文台搭载的软X射线光谱仪（SXS）获得的1.8–20.0 keV数据，研究Perseus星系团核心X射线发射等离子体的温度结构。共进行了四次观测，总有效曝光时间338 ks，覆盖直径约7'的中心区域。SXS在5.9 keV处能量分辨率约5 eV（半高全宽）运行。从Si到Fe的He样离子K壳层细结构线以及更高主量子数跃迁均被清晰分辨。这使我们能利用Si、S、Ar、Ca与Fe的线比进行温度诊断，并首次直接测量Perseus星系团中的激发温度与电离温度。观测能谱大致可由碰撞电离平衡下的单温度热等离子体模型重现，但细致线比诊断揭示出对该近似的轻微偏离。特别是，数据呈现出电离温度随原子质量增大而升高的明显趋势，以及Fe（唯一可同时测两温度的元素）电离与激发温度间的小差异。最佳拟合双温度模型提示3 keV与5 keV气体的组合，这与如下观点一致：观测到的单温度近似微小偏离源于沿视线方向星系团核心已知径向温度梯度的投影效应。另一方面，与Chandra/ACIS及XMM-Newton/RGS结果比较表明，ICM中存在额外低温成分，但Hitomi SXS因其1.8–20 keV能段而无法探测。
引用
@article{arxiv.1712.06612,
title = {Temperature Structure in the Perseus Cluster Core Observed with Hitomi},
author = {Hitomi Collaboration and Felix Aharonian and Hiroki Akamatsu and Fumie Akimoto and Steven W. Allen and Lorella Angelini and Marc Audard and Hisamitsu Awaki and Magnus Axelsson and Aya Bamba and Marshall W. Bautz and Roger Blandford and Laura W. Brenneman and Gregory V. Brown and Esra Bulbul and Edward M. Cackett and Maria Chernyakova and Meng P. Chiao and Paolo S. Coppi and Elisa Costantini and Jelle de Plaa and Cor P. de Vries and Jan-Willem den Herder and Chris Done and Tadayasu Dotani and Ken Ebisawa and Megan E. Eckart and Teruaki Enoto and Yuichiro Ezoe and Andrew C. Fabian and Carlo Ferrigno and Adam R. Foster and Ryuichi Fujimoto and Yasushi Fukazawa and Maki Furukawa and Akihiro Furuzawa and Massimiliano Galeazzi and Luigi C. Gallo and Poshak Gandhi and Margherita Giustini and Andrea Goldwurm and Liyi Gu and Matteo Guainazzi and Yoshito Haba and Kouichi Hagino and Kenji Hamaguchi and Ilana M. Harrus and Isamu Hatsukade and Katsuhiro Hayashi and Takayuki Hayashi and Kiyoshi Hayashida and Junko S. Hiraga and Ann Hornschemeier and Akio Hoshino and John P. Hughes and Yuto Ichinohe and Ryo Iizuka and Hajime Inoue and Yoshiyuki Inoue and Manabu Ishida and Kumi Ishikawa and Yoshitaka Ishisaki and Masachika Iwai and Jelle Kaastra and Tim Kallman and Tsuneyoshi Kamae and Jun Kataoka and Yuichi Kato and Satoru Katsuda and Nobuyuki Kawai and Richard L. Kelley and Caroline A. Kilbourne and Takao Kitaguchi and Shunji Kitamoto and Tetsu Kitayama and Takayoshi Kohmura and Motohide Kokubun and Katsuji Koyama and Shu Koyama and Peter Kretschmar and Hans A. Krimm and Aya Kubota and Hideyo Kunieda and Philippe Laurent and Shiu-Hang Lee and Maurice A. Leutenegger and Olivier Limousin and Michael Loewenstein and Knox S. Long and David Lumb and Greg Madejski and Yoshitomo Maeda and Daniel Maier and Kazuo Makishima and Maxim Markevitch and Hironori Matsumoto and Kyoko Matsushita and Dan McCammon and Brian R. McNamara and Missagh Mehdipour and Eric D. Miller and Jon M. Miller and Shin Mineshige and Kazuhisa Mitsuda and Ikuyuki Mitsuishi and Takuya Miyazawa and Tsunefumi Mizuno and Hideyuki Mori and Koji Mori and Koji Mukai and Hiroshi Murakami and Richard F. Mushotzky and Takao Nakagawa and Hiroshi Nakajima and Takeshi Nakamori and Shinya Nakashima and Kazuhiro Nakazawa and Kumiko K. Nobukawa and Masayoshi Nobukawa and Hirofumi Noda and Hirokazu Odaka and Takaya Ohashi and Masanori Ohno and Takashi Okajima and Naomi Ota and Masanobu Ozaki and Frits Paerels and Stéphane Paltani and Robert Petre and Ciro Pinto and Frederick S. Porter and Katja Pottschmidt and Christopher S. Reynolds and Samar Safi-Harb and Shinya Saito and Kazuhiro Sakai and Toru Sasaki and Goro Sato and Kosuke Sato and Rie Sato and Makoto Sawada and Norbert Schartel and Peter J. Serlemtsos and Hiromi Seta and Megumi Shidatsu and Aurora Simionescu and Randall K. Smith and Yang Soong and Łukasz Stawarz and Yasuharu Sugawara and Satoshi Sugita and Andrew Szymkowiak and Hiroyasu Tajima and Hiromitsu Takahashi and Tadayuki Takahashi and Shiníchiro Takeda and Yoh Takei and Toru Tamagawa and Takayuki Tamura and Takaaki Tanaka and Yasuo Tanaka and Yasuyuki T. Tanaka and Makoto S. Tashiro and Yuzuru Tawara and Yukikatsu Terada and Yuichi Terashima and Francesco Tombesi and Hiroshi Tomida and Yohko Tsuboi and Masahiro Tsujimoto and Hiroshi Tsunemi and Takeshi Go Tsuru and Hiroyuki Uchida and Hideki Uchiyama and Yasunobu Uchiyama and Shutaro Ueda and Yoshihiro Ueda and Shiníchiro Uno and C. Megan Urry and Eugenio Ursino and Shin Watanabe and Norbert Werner and Dan R. Wilkins and Brian J. Williams and Shinya Yamada and Hiroya Yamaguchi and Kazutaka Yamaoka and Noriko Y. Yamasaki and Makoto Yamauchi and Shigeo Yamauchi and Tahir Yaqoob and Yoichi Yatsu and Daisuke Yonetoku and Irina Zhuravleva and Abderahmen Zoghbi},
journal= {arXiv preprint arXiv:1712.06612},
year = {2018}
}
备注
29 pages, 19 figures, 9 tables. Accepted for publication in PASJ