The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Abstract
Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.
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Cite
@article{arxiv.1607.04487,
title = {The Quiescent Intracluster Medium in the Core of the Perseus Cluster},
author = {Hitomi Collaboration and Felix Aharonian and Hiroki Akamatsu and Fumie Akimoto and Steven W. Allen and Naohisa Anabuki and Lorella Angelini and Keith Arnaud and Marc Audard and Hisamitsu Awaki and Magnus Axelsson and Aya Bamba and Marshall Bautz and Roger Blandford and Laura Brenneman and Gregory V. Brown and Esra Bulbul and Edward Cackett and Maria Chernyakova and Meng Chiao and Paolo Coppi and Elisa Costantini and Jelle de Plaa and Jan-Willem den Herder and Chris Done and Tadayasu Dotani and Ken Ebisawa and Megan Eckart and Teruaki Enoto and Yuichiro Ezoe and Andrew Fabian and Carlo Ferrigno and Adam Foster and Ryuichi Fujimoto and Yasushi Fukazawa and Akihiro Furuzawa and Massimiliano Galeazzi and Luigi 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 Harrus and Isamu Hatsukade and Katsuhiro Hayashi and Takayuki Hayashi and Kiyoshi Hayashida and Junko Hiraga and Ann Hornschemeier and Akio Hoshino and John Hughes and Ryo Iizuka and Hajime Inoue and Yoshiyuki Inoue and Kazunori Ishibashi and Manabu Ishida and Kumi Ishikawa and Yoshitaka Ishisaki and Masayuki Itoh and Naoko Iyomoto and Jelle Kaastra and Timothy Kallman and Tuneyoshi Kamae and Erin Kara and Jun Kataoka and Satoru Katsuda and Junichiro Katsuta and Madoka Kawaharada and Nobuyuki Kawai and Richard Kelley and Dmitry Khangulyan and Caroline Kilbourne and Ashley King and Takao Kitaguchi and Shunji Kitamoto and Tetsu Kitayama and Takayoshi Kohmura and Motohide Kokubun and Shu Koyama and Katsuji Koyama and Peter Kretschmar and Hans Krimm and Aya Kubota and Hideyo Kunieda and Philippe Laurent and Francois Lebrun and Shiu-Hang Lee and Maurice Leutenegger and Olivier Limousin and Michael Loewenstein and Knox S. Long and David Lumb and Grzegorz Madejski and Yoshitomo Maeda and Daniel Maier and Kazuo Makishima and Maxim Markevitch and Hironori Matsumoto and Kyoko Matsushita and Dan McCammon and Brian McNamara and Missagh Mehdipour and Eric Miller and Jon Miller and Shin Mineshige and Kazuhisa Mitsuda and Ikuyuki Mitsuishi and Takuya Miyazawa and Tsunefumi Mizuno and Hideyuki Mori and Koji Mori and Harvey Moseley and Koji Mukai and Hiroshi Murakami and Toshio Murakami and Richard Mushotzky and Ryo Nagino and Takao Nakagawa and Hiroshi Nakajima and Takeshi Nakamori and Toshio Nakano and Shinya Nakashima and Kazuhiro Nakazawa and Masayoshi Nobukawa and Hirofumi Noda and Masaharu Nomachi and Steve O'Dell and Hirokazu Odaka and Takaya Ohashi and Masanori Ohno and Takashi Okajima and Naomi Ota and Masanobu Ozaki and Frits Paerels and Stephane Paltani and Arvind Parmar and Robert Petre and Ciro Pinto and Martin Pohl and F. Scott Porter and Katja Pottschmidt and Brian Ramsey and Christopher Reynolds and Helen Russell and Samar Safi-Harb and Shinya Saito and Kazuhiro Sakai and Hiroaki Sameshima and Goro Sato and Kosuke Sato and Rie Sato and Makoto Sawada and Norbert Schartel and Peter Serlemitsos and Hiromi Seta and Megumi Shidatsu and Aurora Simionescu and Randall Smith and Yang Soong and Lukasz Stawarz and Yasuharu Sugawara and Satoshi Sugita and Andrew Szymkowiak and Hiroyasu Tajima and Hiromitsu Takahashi and Tadayuki Takahashi and Shin'ichiro Takeda and Yoh Takei and Toru Tamagawa and Keisuke Tamura and Takayuki Tamura and Takaaki Tanaka and Yasuo Tanaka and Yasuyuki Tanaka and Makoto 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 Tsuru and Hiroyuki Uchida and Hideki Uchiyama and Yasunobu Uchiyama and Shutaro Ueda and Yoshihiro Ueda and Shiro Ueno and Shin'ichiro Uno and Meg Urry and Eugenio Ursino and Cor de Vries and Shin Watanabe and Norbert Werner and Daniel Wik and Dan Wilkins and Brian Williams and Shinya Yamada and Hiroya Yamaguchi and Kazutaka Yamaok and Noriko Y. Yamasaki and Makoto Yamauchi and Shigeo Yamauchi and Tahir Yaqoob and Yoichi Yatsu and Daisuke Yonetoku and Atsumasa Yoshida and Takayuki Yuasa and Irina Zhuravleva and Abderahmen Zoghbi},
journal= {arXiv preprint arXiv:1607.04487},
year = {2016}
}
Comments
31 pages, 11 Figs, published in Nature July 8