New LOFAR detection in the galaxy cluster A1413: connection between non-thermal and thermal emission

Clusters of galaxies are the largest virialized systems in the Universe and thus are ideal laboratories to study the formation and evolution of cosmic structures. The intracluster medium (ICM), a plasma which has been heated, through gravitational collapse, up to temperatures of tens of millions degrees at density of few hundreds particles per cubic meter, emitting mostly in the X-ray band. At the same time, radio observations have proved that the ICM is mixed with a non-thermal component, i.e. highly relativistic particles and large-scale magnetic fields, detected through their synchrotron emission. This non-thermal component is linked to the cluster X-ray properties and understanding its origin is crucial for a comprehensive physical description of the ICM. In the last years, with the advent of new generation low-frequency radio telescopes, the classical dichotomy that connects merging events with giant halos and relaxed cool-core systems with mini-halos, has started to be questioned. In contrast to what has been generally believed, cluster-scale radio emission has also been observed in clusters with no sign of major mergers, indicating that minor mergers and/or sloshing of a dense cool core could trigger particle acceleration on larger scales and generate steep-spectrum radio emission. This work is dedicated to the peculiar galaxy cluster Abell 1413 that we discover to host a non-common radio emission. A1413 is a massive , hot, and nearby (z=0.1427) galaxy cluster. We performed a new study of A1413 with two main goals: (i) to characterize separately the thermal and non-thermal properties of the cluster; (ii) to understand the origin of the radio-emitting electrons through a combined radio and X-ray analysis.