Radio Relics in Cosmological Simulations

Journal of astrophysics and astronomy

S. Gottlöber¹  H. J. A. Röttgering³  S. E. Nuza¹  M. Brüggen⁴  M. Hoeft1²  R. J. van Weeren³ 

[1] Leibniz-Institut für Astrophysik Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany.$$;Thüringer Landessternwarte, Sternwarte 5, 07778, Tautenburg, Germany.$$;Sterrewacht Leiden, P.O. Box 9513, 2300 RA Leiden, The Netherlands.$$;Jacobs University Bremen, Campus Ring 1, 28725 Bremen, Germany.$$

关键词: Cosmology: large-scale structure of the Universe;    galaxies: clusters: general;    intracluster medium.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

Radio relics have been discovered in many galaxy clusters. They are believed to trace shock fronts induced by cluster mergers. Cosmological simulations allow us to study merger shocks in detail since the intra-cluster medium is heated by shock dissipation. Using high resolution cosmological simulations, identifying shock fronts and applying a parametric model for the radio emission allows us to simulate the formation of radio relics. We analyze a simulated shock front in detail. We find a rather broad Mach number distribution. The Mach number affects strongly the number density of relativistic electrons in the downstream area, hence, the radio luminosity varies significantly across the shock surface. The abundance of radio relics can be modeled with the help of the radio power probability distribution which aims at predicting radio relic number counts. Since the actual electron acceleration efficiency is not known, predictions for the number counts need to be normalized by the observed number of radio relics. For the characteristics of upcoming low frequency surveys we find that about thousand relics are awaiting discovery.

【 授权许可】

Unknown