The Radio Emission from Galaxies in the Perseus Cluster

Abstract

Observations of the Perseus cluster have revealed a remarkable interaction between the Seyfert galaxy NGC 1275 and two other galaxies NGC 1265 and IC 310, which lie at distances of about 600 kpc from NGC 1275. The interaction is almost certainly due to the incidence of relativistic particles ejected from the nucleus of NGC 1275 on the gaseous material in these galaxies. Estimates of the minimum energy in the particle stream at epochs ∼ 5.10 ⁶ years ago may be compared with those derived from three radio components associated with NGC 1275 itself, and from a fourth more extensive source. The results suggest that ejection of relativistic particles from the nucleus has continued for the whole of this period, although the present rate is probably rather smaller than that 5.10 ⁶ years ago. The total energy contained in the electronic component is at least 3.10 ⁵⁹ ergs so that it is comparable with that released in the most powerful radio sources known. The acceleration of these particles may be related to a series of supernova events in the nucleus of NGC 1275, occurring at the present time at a rate of about one every 10 years. It seems possible that the source of energy in QSS and radio galaxies may be due to a similar process operating on a shorter time scale.