Dependence of X-ray loudness of AGN on Eddington ratio and black hole mass

In this paper we present the preliminary results of an investigation into the X-ray properties of radio-loud (RL) and radio-quiet (RQ) quasars, since the largest differences in accretion structure of these objects are expected to be imprinted in the UV and X-ray spectra. Using the SDSS DR7 Quasar catalog and Second ROSAT all-sky survey (2RXS) data we demonstrate strong anti-correlation of X-ray loudness on the Eddington ratio, for both RL and RQ AGNs. RL AGNs are found to be on average X-ray louder than RQ AGN (Active Galactic Nuclei), which agrees with previous studies. We also see a dependence of the X-ray loudness on the black hole mass for both our samples. Our results are discussed in the context of theories of the X-ray production in AGN.