Extended X-ray emission in the radio loud galaxy 3C 382

Abstract

ROSAT/HRI observations of the powerful radio-loud galaxy 3C382 reveal extended X-ray emission associated with the source. On the basis of this new spatial component, a previous ROSAT/PSPC spectral analysis of the source is revised. Allowing for the presence of an additional thermal component in the PSPC spectrum, the non-thermal component is found to be compatible with the extrapolation of the well defined 3C382 - 2-10 keV - power-law spectrum into the soft X-rays. The thermal -extended- component would then account for the soft excess emission previously reported for this source. The origin of this thermal component is not clear. Its luminosity compares with that of rich Abell clusters; yet, the galaxy environment in 3C382 appears of moderate optical richness. An alternative is that it is due to a massive extended gaseous atmosphere sustained by the deep gravitational potential well of 3C382.