X-ray studies of quasars with the Einstein Observatory. IV - X-ray dependence on radio emission

Using a sample of 114 radio-loud quasars observed with the Einstein Observatory, the authors study the joint dependence of X-ray luminosity on radio and optical luminosities. By comparing these results with those obtained from a large sample of radio-quiet quasars, the authors confirm that radio-loud quasars are, on the average, more X-ray luminous (for a given optical luminosity) than radio-quiet quasars. A detailed statistical analysis of the sample of radio-loud quasars is presented. The data are consistent with radio-loud quasars having a physical component, not directly related to the optical luminosity, which produces the core radio luminosity plus an "extra" X-ray emission. This extra component would dominate the observed X-ray flux in the majority of radio-loud quasars with flat radio spectra.