Magnetic fields in Clusters of Galaxies
  An important area of study of cosmic magnetic fields is on the largest scales, those of clusters of galaxies. In the last decade it has become clear that the intra-cluster medium (ICM) in clusters of galaxies is magnetized and that magnetic fields play a critical role in the cluster formation and evolution. The observational evidence for the existence of cluster magnetic fields is obtained by the diffuse cluster-wide synchrotron radio emission and from rotation measure (RM) studies of extragalactic radio sources located within or behind the clusters. A significant breakthrough in the knowledge of the cluster magnetic fields will be reached through the SKA, owing to its capabilities, in particular the deep sensitivity and the polarization purity. 
L. Feretti (IRA Bologna), M. Johnston-Hollitt (Leiden Obs.)