时间：2017年10月27日 12:15 － 1:45pm

　　地点: 紫台619会议室

　　Science News：

　　报告人：路 佳

　　Journal Club Public Talk:

　　报告人：耿 超

　　报告题目：The quiescent intracluster medium in the core of the Perseus cluster

　　报告摘要：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. I will report the Hitomi’s 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 and infer that a total cluster mass determined from hydrostatic equilibrium in a central region would require little correction for turbulent pressure.

　　主要参考文献：

　　Hitomi Collaboration et al.(2016) Hitomi Collaboration, Aharonian, F., Akamatsu H. et al. 2016, nature, 535, 117

　　Zhuravleva, I. et al. Turbulent heating in galaxy clusters brightest in X-rays. Nature 515, 85–87 (2014).