The diffuse radio filament in the merging system ZwCl 2341.1+0000

TL;DR

This study presents deep VLA radio observations of the merging galaxy system ZwCl 2341.1+0000, revealing extensive diffuse radio emission along filaments, indicating widespread magnetic fields and relativistic particles in large-scale structures.

Contribution

First detailed radio imaging of diffuse emission along filaments in ZwCl 2341.1+0000, suggesting magnetic fields and relativistic particles extend beyond cluster centers.

Findings

Diffuse radio emission spans 2.2 Mpc in the merging system.

Radio emission detected along optical filaments, not just cluster centers.

Possible scenarios include a giant radio halo or merging clusters with halos.

Abstract

In some clusters of galaxies, a diffuse non-thermal emission is present, not obviously associated with any individual galaxy. These sources have been identified as relics, mini-halos, and halos according to their properties and position with respect to the cluster center. Moreover in a few cases have been reported the existence of a diffuse radio emission not identified with a cluster, but with a large scale filamentary region. The aim of this work is to observe and discuss the diffuse radio emission present in the complex merging structure of galaxies ZwCl 2341.1+0000. We have obtained VLA observations at 1.4 GHz to derive a deep radio image of the diffuse emission. Low resolution VLA images show a diffuse radio emission associated to the complex merging region with a largest size = 2.2 Mpc. In addition to the previously reported peripheral radio emission, classified as a double relic, diffuse emission is detected along the optical filament of galaxies. The giant radio source discussed here shows that magnetic fields and relativistic particles are present also in filamentary structures. Possible alternate scenarios are: a giant radio halo in between two symmetric relics, or the merging of two clusters both hosting a central radio halo.