The Gaseous Environments of Radio Galaxies

Abstract

X-ray emission traces the gaseous environments of radio sources. The medium must be present for jet confinement, but what are its influence on jet fuelling, dynamics, propagation, and disruption? The observational situation is both complicated and enriched by radio sources being multi-component X-ray emitters, with several possible regions of non-thermal emission. Recent work, primarily based on sensitive ROSAT pointings, is used to contrast the X-ray emission and environments of radio sources with (a) low power, (b) high power at high redshift, (c) high power at lower redshift, and (d) GHz peaked spectrum emission. The trends in external gas density and pressure near extended radio structures are reviewed. Imminently-available X-ray measurements with vastly improved resolution and sensitivity have great potential for resolving many open issues.