A 600 kpc complex radio source at the center of Abell 3718 discovered by the EMU and POSSUM surveys

TL;DR

This study presents the discovery and analysis of a 612 kpc radio source in galaxy cluster Abell 3718, using multifrequency radio, optical, and X-ray data to explore its origin and the cluster's dynamical state.

Contribution

It reports the first multifrequency analysis of a large radio source in Abell 3718, revealing insights into its origin and the cluster's merger activity.

Findings

Discovered a 612 kpc radio source in Abell 3718.

Analyzed spectral index from 943 MHz to 9 GHz.

Assessed polarization to understand source nature.

Abstract

Multifrequency studies of galaxy clusters are crucial for inferring their dynamical states and physics. Moreover, these studies allow us to investigate cluster-embedded sources, whose evolution is affected by the physical and dynamical condition of the cluster itself. So far, these kinds of studies have been preferentially conducted on clusters visible from the northern hemisphere due to the high-fidelity imaging capabilities of ground-based radio interferometers located there. In this paper, we conducted a multifrequency study of the poorly known galaxy cluster Abell 3718. We investigated the unknown origin of an extended radio source with a length of $\sim$612 kpc at 943 MHz detected in images from the Evolutionary Map of the Universe (EMU) and POlarisation Sky Survey of the Universe's Magnetism (POSSUM) surveys. We analyzed optical and X-ray data to infer the dynamical state of the cluster and, in particular, the merger activity. We conducted a radio spectral index study from 943 MHz up to 9 GHz. We also evaluated the polarization properties of the brightest cluster-embedded sources to understand if they are related to the radio emission observed on larger scales. [Abstract truncated due to arxiv limit! Please see the pdf version]