Tailed radio galaxies as tracers of galaxy clusters. Serendipitous discoveries with the GMRT

TL;DR

This study reports the serendipitous discovery of four tailed radio galaxies in GMRT data, demonstrating their effectiveness as tracers for identifying galaxy clusters at various redshifts.

Contribution

The paper presents new discoveries of tailed radio galaxies in GMRT observations and confirms their association with rich galaxy environments, highlighting their utility in cluster detection.

Findings

All four tailed radio galaxies are in rich environments.

Two galaxies are associated with a candidate cluster at z=0.075.

One galaxy probes an undetected galaxy cluster at z=0.118.

Abstract

We report on the discovery of four new radio galaxies with tailed morphology. Tailed radio galaxies are generally found in rich environments, therefore their presence can be used as tracer of a cluster. The radio galaxies were found in the fields of Giant Metrewave Radio Telescope (GMRT) observations carried out at 610 MHz and 327 MHz devoted to other studies. We inspected the literature and archives in the optical and X-ray bands to search for galaxy clusters or groups hosting them. All the tailed radio galaxies serendipitously found in the GMRT fields are located in rich environments. Two of them belong to the candidate cluster NCS J090232+204358, located at z(phot)=0.0746; one belongs to the cluster MaxBCGJ223.97317+22.15620 at z(phot)=0.2619; finally we suggest that the fourth one is probing a galaxy cluster at z=0.1177, located behind A262, and so far undetected in any band. Our results strenghten the relevance of high sensitivity and high resolution radio data in the detection of galaxy clusters at intermediate redshift.