The Merging Galaxy Cluster Environment Affects the Morphology of Radio-AGN

TL;DR

This study shows that galaxy cluster mergers influence the morphology of radio-AGN, increasing disturbed and radio-only detected sources, indicating environmental effects on AGN evolution.

Contribution

It provides new evidence that merging galaxy clusters significantly impact the morphology and detection properties of radio-AGN compared to relaxed clusters.

Findings

Higher proportion of disturbed radio-AGN in merging clusters

More radio-only detected AGN in merging environments

Merging clusters influence specific radio-AGN properties

Abstract

It has previously been found that the galaxy cluster environment can affect the fueling and evolution of Active Galactic Nuclei (AGN). This work examines the effect of the merging cluster environment on the properties of radio-AGN by comparing the radio morphology of cluster members in a sample of four merging and eight relaxed galaxy clusters at low redshift (z<0.2). Using 144-MHz data from the LOFAR Two-metre Sky Survey (LoTSS) and Zooniverse, we classify the radio morphology of the radio-detected cluster members using the following morphology classes: compact, compact extended, extended, jetted, and disturbed. We find that the merging cluster environment has a statistically significant, higher population proportion of disturbed (bent and head tail) sources, indicating that the merging environment can affect the morphology of cluster radio-AGN. We also investigate the number of AGN that are detected in the radio data only, and the number that are detected in both the radio and optical data in mergers and non-mergers. We find that the merging cluster environment has a higher population proportion of AGN that are identified only as radio-AGN compared to AGN that are identified as both radio and optical AGN. Overall, we find that the merging environment affects certain radio-AGN (disturbed and only radio identified AGN), but not all.