The Optical Properties of Host Galaxies of Radio Sources in the Coma Cluster

TL;DR

This study investigates the optical and radio properties of 79 host galaxies of radio sources in the Coma cluster, revealing correlations between morphology, galaxy type, and environmental location, and highlighting the impact of ram pressure stripping.

Contribution

It combines deep LOFAR radio data with optical spectroscopy and photometry to classify radio sources and analyze their distribution and properties within the cluster environment.

Findings

Compact radio sources are associated with massive, quiescent galaxies with AGN activity.

Tailed sources are mainly in star-forming galaxies undergoing ram pressure stripping.

Extended sources are found in the cluster outskirts, indicating environmental influence.

Abstract

We present a comprehensive study of host galaxies of radio sources within the 1.35$R_{200}$ of the Coma cluster by combining deep 144MHz observations from the LOFAR Two-Metre Sky Survey (LoTSS-DR2) with optical spectroscopy and photometry from DESI and SDSS. We identify 79 spectroscopically confirmed cluster members with reliable radio emission and classify them into compact, extended, and tailed subsamples according to their radio morphologies. By combining their radio and optical properties, we find compact radio sources are predominantly associated with massive, quiescent galaxies driven by AGN activity, while tailed sources are largely hosted by star-forming galaxies, tracing ongoing ram pressure stripping (RPS). Using phase-space analysis and a projected infall time proxy ($d_R$), we find that extended sources are preferentially located in the cluster outskirts ($d_R > 1$), while tailed sources are concentrated in the intermediate infall region ($0.4 < d_R < 1.0$), highlighting the influence of the dense intracluster medium.