Radio galaxies as probes of the large-scale external medium

Abstract

Radio galaxies are well-known probes of the ambient medium. Here I describe recent studies showing correlations between radio galaxy morphologies and their galaxy hosts and environments that point to the possibility of their being potentially useful probes of the large-scale external medium. Set in the context of origin of X-shaped structures I present results of a study in which the morphologies and linear sizes of radio galaxies on scales of several tens of kiloparsecs appear to be strongly affected by the relative orientation of jets and host galaxy axes. On larger scales, it is shown how giant radio galaxies may be a novel means of tracing and probing the elusive WHIM, within which they are embedded.