1995A&A...298..420S

We present ROSAT PSPC observations of the compact group Stephan's Quintet (HCG 92). Our 17.8ksec observation recorded 673 photons from the group. Diffuse emission is detected from a source with diameter D∼6.5arcmin centered on the group. This is strong evidence that at least four of the galaxies are part of a physically dense aggregate. X-ray emission is also seen extending toward the low-redshift member of the group, NGC 7320. The hot diffuse component could arise from gas that has been stripped from the individual galaxies if frequent close encounters occur in this compact group. This interpretation is discussed from the standpoint of the source morphology, luminosity, mass and inferred near solar abundance of the X-ray gas. We also detect a somewhat harder component near the Seyfert nucleus of NGC 7319.