The role of cosmic rays, magnetic fields, and turbulence in AGN feedback
报告人（单位）
Prof. Mateusz Ruszkowski（University of Michigan）
报告时间
2022年5月19日（周四）15:00
主办方
中科院上海天文台
直播二维码
报告人介绍
Prof. Ruszkowski did his PhD at the Institute of Astronomy in the University of Cambridge in the UK, where he was affiliated with Trinity College. He continued his career as a Chandra Fellow and Senior Research Associate at the University of Colorado at Boulder in the US and, subsequently, as a postdoctoral fellow at the Max Planck Institute for Astrophysics in Garching, Germany. Prof. Ruszkowski is a faculty member at the University of Michigan in Ann Arbor in the US, and is currently on a sabbatical leave at the MPA in Garching. He is a theoretical astrophysicist and his main area of expertise is in the physics of feedback from supermassive black holes and stellar sources (AGN and galactic winds), astrophysical MHD, and cosmic rays.
报告摘要
AGN play central role in shaping the properties of galaxies and solving the decades-old cooling flow problem. In this talk, I will discuss recent developments in the field of AGN jet feedback. I will focus on the role of cosmic rays, magnetic fields, and turbulence in shaping the observational properties of hot gaseous halos and on theoretical aspects of the energy transfer from the AGN jets to the ambient medium, i.e., the circumgalactic and intracluster medium (CGM and ICM, respectively). I will begin by discussing an example of supermassive black hole (SMBH) feedback in our own Galactic ``backyard'' — the Fermi Bubbles observed by Fermi in gamma-rays, Planck in microwaves, and, most recently, by eROSITA in X-rays. I will then discuss AGN jet feedback in elliptical galaxies and galaxy clusters. Specifically, I will discuss three new surprising findings: (i) that cosmic ray streaming heating is an important new channel for the AGN energy thermalization in the feedback process, (ii) that even extremely weak magnetic fields can dramatically alter the dynamics of the cold gas precipitation out of the CGM and ICM and feeding the SMBH, and (iii) that, contrary to textbook expectation, turbulence in the CGM/ICM may be non-Kolmogorov in nature. All of these findings have implications for the interpretation of observational results and for our understanding of AGN feedback in general.