Turning AGN Bubbles into Radio Relics with Sloshing: Modeling CR Transport with Realistic Physics

Galaxies

卷:9

Rainer Weinberger¹  John ZuHone²  Kristian Ehlert³  Christoph Pfrommer³ 

[1] Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8, Canada;

[2] Center for Astrophysics

[3] Harvard & Smithsonian, 60 Garden St., Cambridge, MA 02138, USA;

[4] Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany;

关键词: galaxy clusters;    extragalactic radio sources;    cosmic rays;    magnetohydrodynamical simulations;   

DOI  :  10.3390/galaxies9040091

来源: DOAJ

【 摘 要 】

Radio relics are arc-like synchrotron sources at the periphery of galaxy clusters, produced by cosmic-ray electrons in a $\mathsf{\mu }$G magnetic field, which are believed to have been (re-)accelerated by merger shock fronts. However, not all relics appear at the same location as shocks as seen in the X-ray. In a previous work, we suggested that the shape of some relics may result from the pre-existing spatial distribution of cosmic-ray electrons, and tested this hypothesis using simulations by launching AGN jets into a cluster atmosphere with sloshing gas motions generated by a previous merger event. We showed that these motions could transport the cosmic ray-enriched material of the AGN bubbles to large radii and stretch it in a tangential direction, producing a filamentary shape resembling a radio relic. In this work, we improve our physical description for the cosmic rays by modeling them as a separate fluid which undergoes diffusion and Alfvén losses. We find that, including this additional cosmic ray physics significantly diminishes the appearance of these filamentary features, showing that our original hypothesis is sensitive to the modeling of cosmic ray physics in the intracluster medium.

【 授权许可】

Unknown