Radio Halos, cluster mergers and the role of future LOFAR observations

TL;DR

This paper discusses the observed bimodality of radio halos in galaxy clusters, linking it to cluster mergers, and explores how future LOFAR observations can enhance understanding of their properties and origins.

Contribution

It provides detailed evidence connecting radio bimodality to cluster dynamics and discusses the potential of LOFAR surveys to advance knowledge of radio halo formation.

Findings

Radio bimodality correlates with cluster dynamical states

Cluster mergers are key to giant radio halo generation

LOFAR surveys will improve statistical understanding of radio halos

Abstract

A radio bimodality is observed in galaxy clusters: a fraction of clusters host giant radio halos while the majority of clusters do not show evidence of diffuse cluster-scale radio emission. Present data clearly suggest that the radio bi-modality has a correspondence in terms of dynamical state of the hosting clusters. I will report on these evidences in some details and discuss the role of cluster mergers in the generation of giant radio halos and their evolution. Finally I will report on expectations on the statistical properties of radio halos assuming that the emitting electrons are re-accelerated by merger-turbulence, and discuss the role of incoming LOFAR surveys.