1996A&A...309...75M

We report X-ray obervations of the radio galaxy B2 1122+39 (NGC 3665), associated with two radio jets, carried out by the Rosat PSPC and HRI instruments. We have detected extended X-ray emission, with a brightness profile consistent with a β hydrostatic model, that originates from a hot corona (kT≃0.5) that surrounds the galaxy. These X-ray data, combined with VLA radio observations, lead to conclude that the thermal pressure of the hot gas is larger than the jet equipartition pressure of relativistic electrons, implying that the assumptions made in the computation of the internal pressure may not be valid. The jet structure has been satisfactorily modeled assuming that the jets are confined by the X-ray emitting atmosphere. We also found that the amount of dark matter in the galactic corona is negligible.