XMM-Newton Observation of IC 310 in the Outer Region of the Perseus Cluster of Galaxies
K. Sato, T. Furusho, N. Y. Yamasaki, M. Ishida, K. Matsushita, T. Ohashi
Abstract
We present results from an XMM-Newton observation of the head-tail radio galaxy IC 310 located in the southwest region of the Perseus cluster. The spectrum is well-fitted by an absorbed power-law model with a photon index of
2.50±0.02
with no significant absorption excess. The X-ray image shows a point-like emission at IC 310 without any signs of a structure correlated with the radio halo tail. The temperature of the intracluster medium surrounding IC 310 declines as a function of distance from the cluster center, from
kT∼6
keV in the northeast corner of the field of view to about 3 keV in the southwest region. Although we do not find any sharp edges in the surface brightness profile, a brightness excess over a smooth
β
model by about 20% is seen. The temperature also rises by about 10% in the same region. This indicates that the IC 310 region is a subcluster probably infalling into the Perseus cluster, and the gas in front of IC 310 towards the Perseus cluster is likely to be compressed by the large-scale motion, which supports the view that the IC 310 system is undergoing a merger.