The Connection between Radio Halos and Cluster Mergers and the Statistical Properties of the Radio Halo Population

Journal of astrophysics and astronomy

G. Brunetti¹  T. Venturi¹  R. Cassano1 2² 

[1] IRA-INAF, via Gobetti 101, 40129 Bologna, Italy.$$;Dipartimento di Astronomia, Università di Bologna, via Ranzani 1, 40127, Bologna, Italy.$$

关键词: Galaxy: clusters: general;    radio continuum: general;    X-rays: general;    radiation mechanisms: non-thermal.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

We discuss the statistical properties of the radio halo population in galaxy clusters. Radio bi-modality is observed in galaxy clusters: a fraction of clusters host giant radio halos while a majority of clusters do not show evidence of diffuse cluster-scale radio emission. The radio bi-modality has a correspondence in terms of dynamical state of the hosting clusters showing that merging clusters host radio halos and follow the well-known radio-X-ray correlation, while more relaxed clusters do not host radio halos and populate a region well separated from that correlation. These evidences can be understood in the framework of a scenario wheremerger-driven turbulence re-accelerate the radio emitting electrons. We discuss the main statistical expectations of this scenario underlining the important role of the upcoming LOFAR surveys to test present models.

【 授权许可】

Unknown