Radio observations of ZwCl 2341.1+0000: a double radio relic cluster

TL;DR

This study presents radio observations of the merging galaxy cluster ZwCl 2341.1+0000, revealing a double radio relic structure that indicates shock waves from a merger, with detailed spectral and magnetic field analysis.

Contribution

First detailed radio imaging of ZwCl 2341.1+0000 revealing a double relic structure linked to merger shocks.

Findings

Detection of a double radio relic in ZwCl 2341.1+0000

Spectral indices of -0.49 and -0.76 for the relics

Magnetic field strength estimated between 0.48 and 0.93 microGauss

Abstract

Context: Hierarchal models of large scale structure (LSS) formation predict that galaxy clusters grow via gravitational infall and mergers of (smaller) mass concentrations, such as clusters and galaxy groups. Diffuse radio emission, in the form of radio halos and relics, is found in clusters undergoing a merger, indicating that shocks or turbulence associated with the merger are capable of accelerating electrons to highly relativistic energies. Here we report on radio observations of ZwCl 2341.1+0000, a complex merging structure of galaxies located at z=0.27, using Giant Metrewave Radio Telescope (GMRT) observations. Aims: The main aim of the observations is to study the nature of the diffuse radio emission in the galaxy cluster ZwCl 2341.1+0000. Methods: We have carried out GMRT 610, 241, and 157 MHz continuum observations of ZwCl 2341.1+0000. The radio observations are combined with X-ray and optical data of the cluster. Results: The GMRT observations show the presence of a double peripheral radio relic in the cluster ZwCl 2341.1+0000. The spectral index is -0.49 \pm 0.18 for the northern relic and -0.76 \pm 0.17 for the southern relic respectively. We have derived values of 0.48-0.93 microGauss for the equipartition magnetic field strength. The relics are probably associated with an outwards traveling merger shock waves.