A Feedback Model for Radio Sources Fueled by Cooling Flows

Abstract

In many of galaxies, radiative cooling in the central regions appears to drive an accretion flow. Many of these cooling-flow clusters possess strong radio sources in the central regions, which suggests a causal relation between the cooling flow and the radio source. We consider a general model in which a cooling flow produces and interacts with relativistic electrons in the core of the cluster. These electrons heat the inflowing gas, generating negative feedback that reduces the accretion rate. For sufficiently strong feedback, the accretion flow shows an oscillatory behavior on a timescale of several hundred million years.