A MeerKAT view on galaxy clusters

TL;DR

This paper reviews MeerKAT radio observations of galaxy clusters, testing the turbulent re-acceleration model for radio halo formation, and proposes future surveys to further validate the model across different redshifts.

Contribution

It presents new MeerKAT observations of nearby clusters and outlines future surveys to test radio halo formation models at various redshifts.

Findings

Support for turbulent re-acceleration in small systems

Proposed surveys for high-redshift cluster radio halos

Initial observational evidence aligning with theoretical predictions

Abstract

Almost two decades of observations of radio emission in galaxy clusters have proven the existence of relativistic particles and magnetic fields that generate extended synchrotron emission in the form of radio halos. In the current scenario, radio halos are generated through re--acceleration of relativistic electrons by turbulence generated by cluster mergers. Although this theoretical framework has received increasingly supporting observational evidence over the last ten years, observations of statistically complete samples are needed in order to fundamentally test model predictions. In this paper we briefly review our 7--element Karoo Radio Telescope observations of a sample of nearby clusters aimed to test the predictions of the turbulent re--acceleration model in small systems ($M_{500} > 4 \times 10^{14}$ M$_{\odot}$). We conclude by presenting two galaxy cluster surveys to be carried out with MeerKAT in order to provide crucial test of models of radio halo formation in nearby ($z < 0.1$) and high redshift ($z > 0.4$) systems respectively.