제목: Magnetic Fields, Jets, Velocities, and Cosmic Rays in Merging Galaxy Clusters​​​​​​​​

장소: 과학관 B102호 

Abstract: 

Galaxy clusters are the largest gravitationally bound objects in the current universe, and mergers between them are the current stage of cosmological structure formation. The dominant baryonic component of galaxy clusters is their diffuse, hot, and magnetized intracluster medium (ICM), which is observed in X-rays and the Sunyaev-Zeldovich effect. The non-thermal cosmic-ray and magnetic field components of clusters are primarily probed by radio observations. Even for apparently relaxed clusters, the latest generation of X-ray observatories, including Chandra, XMM-Newton, Suzaku, and Hitomi, have revealed a dynamic ICM as evidenced by cold fronts, surface brightness fluctuations, and the direct observations of gas motions in the Perseus Cluster by Hitomi. Such motions can arise from either merging, AGN feedback, or a complex combination of both. Understanding how all of these processes work together from a theoretical perspective requires numerical magnetohydrodynamical simulations. In this talk, I will show how we model the effects of mergers on galaxy clusters, and how they drive the evolution of the magnetic field and gas velocities, as well as cosmic rays injected by AGN, in such simulations. At the end of the talk, I will provide a short excursus on a newly proposed X-ray mission, the Line Emission Mapper, which holds much promise for probing the properties of the hot plasma not only in clusters but also down to mass scales of Milky Way-mass galaxies.