Radio-continuum jets around the peculiar galaxy pair ESO 295-IG022

TL;DR

This study presents high-resolution radio observations of the peculiar galaxy pair ESO 295-IG022, revealing a double jet structure from one galaxy, with detailed spectral and polarization properties, enhancing understanding of jet morphology in galaxy clusters.

Contribution

First high-resolution radio imaging of ESO 295-IG022's jets, confirming their structure and spectral properties, and analyzing the polarization and core activity in the galaxy pair.

Findings

Confirmed double jet structure from ESO 295-IG022-N

Detected steep spectral index of jet (alpha=-1.32)

Observed high polarization levels up to 70%

Abstract

We report new radio-continuum observations with the Australia Telescope Compact Array (ATCA) of the region surrounding the peculiar galaxy pair ESO 295-IG022, at the centre of the poor cluster Abell S0102. We observed this cluster at wavelengths of lambda=20/13 and 6/3 cm with the ATCA 6 km array. With these configurations, we achieved a resolution of ~2" at 3 cm which is sufficient to resolve the jet-like structure of ~3' length detected at 20 cm. From our new high resolution images at 6 and 3 cm we confirm the presence of a double jet structure, most likely originating from the northern galaxy (ESO295-IG022-N), bent and twisted towards the south. We found the spectral index of the jet to be very steep (alpha=-1.32). No point source was detected that could be associated with the core of ESO 295-IG022-N. On the other hand, ESO 295-IG022-S does not show any jet structure, but does show a point radio source. This source has variable flux and spectral index, and appears to be superposed on the line-of-sight of the jets (seen at 20-cm) originating from the northern galaxy ESO 295-IG022-N. Finally, regions of very high and somewhat well ordered polarisation were detected at the level of 70%.