Separation of X-ray emission components in radio galaxies

One of ROSAT’s major achievements has been its ability to separate X‐ray emission components in many radio galaxies, where this was previously possible only for a very few well‐known sources, e.g.,M87 and Cen A. The dominant X‐ray emission mechanism in radio galaxies as a class was unclear, with correlations between the X‐ray and radio emissions used on one hand to argue for a nuclear origin for the X‐rays, and on the other hand for a thermal origin. Now, with ROSAT we find the presence of both resolved (thermal) and unresolved emission to be typical.Our results are illustrated with PSPC data from the first six radio galaxies in our study. Spectral and spatial measurements independently support the presence of multiple emission components. The resolved emission can be modeled as thermal radiation from gas of galaxy, group, or cluster dimension depending on object. The unresolved emission may be thermal or nonthermal. Evidence is presented to support a nonthermal origin for most of the unresolved emission:...