Radio observations of a hard X-ray selected sample of active galaxies

The authors present radio observations of a hard X-ray selected sample of active galaxies, made with the VLA and Parkes radio telescopes. All of the galaxies observed with the VLA were detected, making this an excellent sample with which to look at the relationship between the radio and X-ray emission from active galaxies. The authors use the ratio of the radio to X-ray flux density as a measure of the degree of "radio-loudness" of an active galaxy. They find no evidence for distinct "radio-quiet" and "radio-loud" populations, rather there is a continuous distribution of the degree of radio-loudness amongst the sample galaxies. The X-ray and radio luminosity are found to be correlated. The correlation is not linear, the radio-loud objects all having high X-ray luminosity.