X-Ray Emission Associated With Radio Galaxies in the Perseus Cluster

In this paper, we report on new x-ray observations of the Perseus cluster made using four separate pointings of the ROSAT PSPC. We searched for x-ray emission associated with 16 radio galaxies and detected six above 3σ. We made use of the PSPC spectra to determine if the x-ray emission associated with radio galaxies in Perseus is thermal or nonthermal in origin (i.e,, hot gas or an AGN). For the head-tail radio galaxy IC 310, we find that the data are best fit by a power law model with an unusually large spectral index α = 2.7. This is consistent with its unresolved spatial structure. On the other hand, a second resolved x-ray source associated with another radio galaxy 2.3 Mpc from the Perseus center (V Zw 331) is best fit by a thermal model. For three sources with insufficient flux for a full spectral analysis, we calculated hardness ratios. On this basis the x-ray emission associated with the well known head-tail source NGC 1265 is consistent with thermal radiation. The x-ray spectra of UGC 2608 and UGC 2654 probably arise from hot gas, although very steep power-law spectra (α > 3.2) are also possible. The spectrum of NGC 1275 is quite complex due to the presence of an AGN and the galaxy's location at the center of a cluster cooling flow.