Radio observations of Planck clusters

TL;DR

This paper reports on radio observations of galaxy clusters detected via the Sunyaev-Zeldovich effect by Planck, leading to the discovery of a new giant radio halo in a recently identified cluster, enhancing understanding of cosmic rays and magnetic fields.

Contribution

First radio detection of a giant radio halo in a newly discovered Planck galaxy cluster, demonstrating the potential of SZ-selected clusters for studying diffuse radio sources.

Findings

Detection of a giant radio halo in PLCKG171.9-40.7

Radio observations confirm presence of diffuse radio sources in SZ-selected clusters

Supports link between cluster mergers and radio halo occurrence

Abstract

Recently, a number of new galaxy clusters have been detected by the ESA-Planck satellite, the South Pole Telescope and the Atacama Cosmology Telescope using the Sunyaev-Zeldovich effect. Several of the newly detected clusters are massive, merging systems with disturbed morphology in the X-ray surface brightness. Diffuse radio sources in clusters, called giant radio halos and relics, are direct probes of cosmic rays and magnetic fields in the intra-cluster medium. These radio sources are found to occur mainly in massive merging clusters. Thus, the new SZ-discovered clusters are good candidates to search for new radio halos and relics. We have initiated radio observations of the clusters detected by Planck with the Giant Metrewave Radio Telescope. These observations have already led to the detection of a radio halo in PLCKG171.9-40.7, the first giant halo discovered in one of the new Planck clusters.