A ROSAT HRI study of the interaction of the X-ray-emitting gas and radio lobes of NGC 1275

A high spatial resolution ROSAT image of NGC 1275 in the center of the Perseus cluster of galaxies shows for the first time clear evidence for the interaction of the relativistic particles in the radio lobes with the X-ray-emitting intracluster plasma. The thermal plasma is displaced by the inner parts of the radio lobes, causing a significant decrease of the X-ray surface brightness in those regions. The equipartition pressure in the radio lobes is somewhat less than the pressure in the surrounding intracluster medium unless a high ratio of relativistic protons to electrons is assumed.