Radio jets and diffuse X-ray emission around the peculiar galaxy pair ESO 295-IG022

Abstract

We report Australia Telescope Compact Array (ATCA) radio-continuum and ROSAT PSPC X-ray observations of the region surrounding the peculiar galaxy pair ESO 295-IG022, lying at the centre of the poor cluster Abell S0102. We identify a radio galaxy coincident with the galaxy pair, with bipolar, bent radio jets appearing centred on the southern galaxy, and extending both to the south, for about 95 arcseconds (approximately 100 kpc at the distance of ESO 295-IG022), and to the north, for approximately 80 arcseconds, encompassing the northern galaxy. We discuss also the idea of an additional single jet structure from the northern galaxy contributing to the emission. We estimate lower limit jet velocities of at least 1000 km/s, and a relative proper velocity for the southern galaxy through the cluster of around 200 km/s. Diffuse (kT=2.2 keV) X-ray emission consistent with group or poor cluster emission is seen centred on the southern galaxy surrounding the galaxy pair and the associated radio jets. Structure within the radio jets and the X-ray emission is very suggestive of there being some channeling of the radio emission with the surrounding intragroup medium. Another bipolar jet radio galaxy, discovered close by, is likely to be a background object, the optical counterpart having a magnitude greater than m=22.