A search for diffuse radio emission in the relaxed, cool-core galaxy clusters A1068, A1413, A1650, A1835, A2029, and Ophiuchus

TL;DR

This study uses deep radio observations to search for diffuse radio emissions in relaxed galaxy clusters, discovering mini-halos in some clusters and a giant radio galaxy, advancing understanding of cluster radio phenomena.

Contribution

The paper provides new high-sensitivity radio observations revealing mini-halos in specific relaxed galaxy clusters and reports a serendipitous giant radio galaxy detection.

Findings

Mini-halos detected in A1835, A2029, and Ophiuchus

No diffuse emission found in A1650

Possible diffuse emission in A1068 and A1413, requiring further study

Abstract

We analyze sensitive, high-dynamic-range, observations to search for extended, diffuse, radio emission in relaxed and cool-core galaxy clusters. We performed deep 1.4 GHz Very Large Array observations, of A1068, A1413, A1650, A1835, A2029, and complemented our dataset with archival observations of Ophiuchus. We find that, in the central regions of A1835, A2029, and Ophiuchus, the dominant radio galaxy is surrounded by diffuse low-brightness radio emission that takes the form of a mini-halo. We detect no diffuse emission in A1650, at a surface brightness level of the other mini-halos. We find low significance indications of diffuse emission in A1068 and A1413, although to be classified as mini-halos they would require further investigation, possibly with data of higher signal-to-noise ratio. In the Appendix, we report on the serendipitous detection of a giant radio galaxy with a total spatial extension of ~1.6 Mpc.