Low-frequency radio observations of the galaxy cluster CIZA J2242.8+5301

TL;DR

This paper presents low-frequency GMRT radio observations of the galaxy cluster CIZA J2242.8+5301, revealing double radio relics and large-scale diffuse emission, supporting the shock wave origin of relics in merging clusters.

Contribution

It provides new low-frequency observations of the cluster, detecting double relics and diffuse emission, advancing understanding of radio relics in galaxy clusters.

Findings

Detection of double radio relics at 150 and 325 MHz

Discovery of large-scale diffuse emission between relics

Supports shock wave origin of radio relics

Abstract

Some disturbed galaxy clusters host diffuse elongated radio sources, also called radio relics. It is proposed that these relics trace shock waves in the intracluster medium (ICM). Within the shock waves, generated by cluster merger events, particles are accelerated to relativistic energies, and in the presence of a magnetic field synchrotron radiation will be emitted. CIZA J2242.8+5301 is a disturbed galaxy cluster hosting complex diffuse radio emission, including a so-called double radio relic. Here we present new Giant Metrewave Radio Telescope (GMRT) radio observations of CIZA J2242.8+5301 at 325 and 150 MHz. We detect the double radio relic at 150 and 325 MHz. The very deep 150 MHz image reveals the presence of large-scale diffuse emission between the two radio relics.