Constraining the central engine of radio-loud AGNs

We present an X-ray spectral survey of radio-loud (RL) AGNs using ASCA and RXTE. The goal was to study the structure of their central engines and compare it to that of their radio-quiet (RQ) counterparts. We find systematic differences in the X-ray properties of the two AGN classes. Specifically, RL AGNs exhibit weaker Fe lines and reflection components than RQ AGNs, indicating smaller solid angles subtended by the re-processing medium to the X-ray source. The circumnuclear environs of RL and RQ AGNs also differ: large amounts of cold gas are detected in Broad Line Radio Galaxies and Quasars, contrary to what is found in Seyfert galaxies of similar X-ray luminosity. We also discuss ASCA observations of Weak Line Radio Galaxies, a distinct subset of radio galaxies which may harbor a low-luminosity AGN powered by an advection-dominated accretion flow. [ABSTRACT FROM AUTHOR]