Galaxy Clusters in the Radio: Relativistic Plasma and ICM/Radio Galaxy Interaction Processes

The organization of this paper is as follows: the basic formulae used to derive the age of synchrotron sources and the equipartition parameters are presented in Section 2, while the observational properties of diffuse radio sources (Radio halos, Radio relics, and Mini-halos) are presented in Section 3. Then in Section 4 we give a general outline of the models of the relativistic particle origin and re-acceleration; while the current results on cluster magnetic fields are described in Section 5. Finally, Section 6 reports the properties of cluster radio emitting galaxies.