The quiescent intracluster medium in the core of the Perseus cluster
2016; Nature Portfolio; Volume: 535; Issue: 7610 Linguagem: Inglês
10.1038/nature18627
ISSN1476-4687
AutoresF. Aharonian, Hiroki Akamatsu, Fumie Akimoto, S. W. Allen, Naohisa Anabuki, L. Angelini, Keith A. Arnaud, M. Audard, Hisamitsu Awaki, M. Axelsson, Aya Bamba, Marshall W. Bautz, R. D. Blandford, Laura Brenneman, G. V. Brown, Esra Bülbül, Edward Cackett, M. Chernyakova, Meng P. Chiao, Paolo De Coppi, E. Costantini, J. de Plaa, Jan-Willem den Herder, Chris Done, Tadayasu Dotani, K. Ebisawa, Megan E. Eckart, Teruaki Enoto, Yuichiro Ezoe, A. C. Fabian, C. Ferrigno, Adam Foster, Ryuichi Fujimoto, Yasushi Fukazawa, Akihiro Furuzawa, M. Galeazzi, Luigi Gallo, Poshak Gandhi, M. Giustini, A. Goldwurm, Liyi Gu, M. Guainazzi, Yoshito Haba, Kouichi Hagino, Kenji Hamaguchi, I. Harrus, Isamu Hatsukade, Katsuhiro Hayashi, Takayuki Hayashi, Kiyoshi Hayashida, Junko S. Hiraga, A. E. Hornschemeier, Akio Hoshino, John P. Hughes, Ryo Iizuka, Hajime Inoue, Yoshiyuki Inoue, Kazunori Ishibashi, M. Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Masayuki Itoh, Naoko Iyomoto, J. S. Kaastra, T. R. Kallman, T. Kamae, Erin Kara, J. Kataoka, Satoru Katsuda, J. Katsuta, Madoka Kawaharada, N. Kawai, Richard L. Kelley, Dmitry Khangulyan, C. A. Kilbourne, Ashley L. King, Takao Kitaguchi, Shunji Kitamoto, Tetsu Kitayama, Takayoshi Kohmura, M. Kokubun, Shu Koyama, Katsuji Koyama, P. Kretschmar, H. Krimm, Aya Kubota, Hideyo Kunieda, Philippe Laurent, F. Lebrun, S.-H. Lee, Maurice A. Leutenegger, Olivier Limousin, Michael Loewenstein, Knox S. Long, David H. Lumb, G. Madejski, Yoshitomo Maeda, Daniel Maier, Kazuo Makishima, M. Markevitch, Hironori Matsumoto, Kyoko Matsushita, D. McCammon, B. R. McNamara, M. Mehdipour, Eric D. Miller, J. M. Mïller, Shin Mineshige, Kazuhisa Mitsuda, Ikuyuki Mitsuishi, Takuya Miyazawa, Tsunefumi Mizuno, Hideyuki Mori, Koji Mori, H. Moseley, K. Mukai, Hiroshi Murakami, Toshio Murakami, R. F. Mushotzky, Ryo Nagino, Takao Nakagawa, Hiroshi Nakajima, Takeshi Nakamori, Toshio Nakano, Shinya Nakashima, K. Nakazawa, Masayoshi Nobukawa, Hirofumi Noda, Masaharu Nomachi, Stephen L. O’Dell, Hirokazu Odaka, Takaya Ohashi, M. Ohno, Takashi Okajima, Naomi Ota, Masanobu Ozaki, F. Paerels, Stéphane Paltani, A. N. Parmar, Robert Petre, C. Pinto, M. Pohl, F. S. Porter, K. Pottschmidt, Brian D. Ramsey, C. S. Reynolds, H. R. Russell, Samar Safi‐Harb, Shinya Saito, Kazuhiro Sakai, Hiroaki Sameshima, Goro Sato, Kosuke Sato, Rie Sato, Makoto Sawada, N. Schartel, P. J. Serlemitsos, Hiromi Seta, M. Shidatsu, A. Simionescu, Randall K. Smith, Yang Soong, Ł. Stawarz, Y. Sugawara, Satoshi Sugita, Andrew E. Szymkowiak, H. Tajima, H. Takahashi, Tadayuki Takahashi, Shin’ichiro Takeda, Yoh Takei, Toru Tamagawa, Keisuke Tamura, Takayuki Tamura, T. Tanaka, Yasuo Tanaka, Yasuyuki Tanaka, M. Tashiro, Yuzuru Tawara, Y. Terada, Yuichi Terashima, Francesco Tombesi, Hiroshi Tomida, Yohko Tsuboi, Masahiro Tsujimoto, H. Tsunemi, Takeshi Go Tsuru, Hiroyuki Uchida, Hideki Uchiyama, Y. Uchiyama, Shutaro Ueda, Yoshihiro Ueda, Shiro Ueno, Shin’ichiro Uno, C. M. Urry, Eugenio Ursino, Cor de Vries, Shin Watanabe, Norbert Werner, Daniel R. Wik, D. R. Wilkins, Brian J. Williams, S. Yamada, Hiroya Yamaguchi, K. Yamaoka, Noriko Y. Yamasaki, M. Yamauchi, Shigeo Yamauchi, Tahir Yaqoob, Yoichi Yatsu, Daisuke Yonetoku, A. Yoshida, Takayuki Yuasa, Irina Zhuravleva, Abderahmen Zoghbi,
Tópico(s)Astrophysics and Star Formation Studies
ResumoX-ray observations of the core of the Perseus cluster reveal a remarkably quiescent atmosphere in which the gas has a line-of-sight velocity dispersion of about 164 kilometres per second in the region 30–60 kiloparsecs from the central nucleus; turbulent pressure support in the gas is four per cent of the thermodynamic pressure, necessitating only a small correction to the total cluster mass determined from hydrostatic equilibrium. The Hitomi collaboration reports X-ray observations of the core of the Perseus cluster of galaxies — the brightest X-ray-emitting cluster in the sky. Such clusters typically consist of tens to thousands of galaxies bound together by gravity and are studied as models of both small-scale cosmology and large-scale astrophysical processes. The data reveal a remarkably quiescent atmosphere, where gas velocities are quite low, with a line-of-sight velocity dispersion of about 164 kilometres per second at a distance of 30–60 kiloparsecs from the central nucleus. Clusters of galaxies are the most massive gravitationally bound objects in the Universe and are still forming. They are thus important probes1 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 feedback2,3,4,5,6. 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.
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