Probing black hole axis perturbations using low axial ratio radio galaxies

Abstract

With the unique advantage that radio galaxies have in delineating the central super-massive black hole axis along their radio axes they make useful probes for unseen central engine processes. In this paper I bring to attention the remarkable power of low axial ratio radio galaxy samples in opening up for examination this hard-to-probe regime of active galaxies. I present results from our recent EVLA observations of a large radio source sample originally selected on the basis of shapes. The observations have revealed a plethora of radio sources that potentially show signatures of axis changes of various types suggesting such samples as effective means for probing black hole axis perturbations and hence such samples to be effective means in searches for binary black hole pairs in radio galaxies.