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We investigate the clustering propertiesof ∼1550 low‐redshift broad‐line AGNs detected in the ROSAT All‐Sky Survey (RASS) through a cross‐correlation function (CCF) with ∼46000 Luminous Red Galaxies (LRGs) in the Sloan Digital Sky Survey (SDSS). Using this approach, we avoid small‐number statistics and systematic errors caused by the variation of the Galactic absorption compared to a direct measurement of the AGN auto‐correlation function (ACF).We compute the ACF of low‐z RASS‐AGN based on the CCF for the total X‐ray sample ( = 0.25) and found a correlation length of r0 = 4.3−0.4+0.4 h−1 Mpc. Furthermore, we discovered an X‐ray luminosity dependence of the clustering signal, i.e. high luminosity AGN cluster stronger than low luminosity AGN. We have also applied a Halo Occupation Distribution (HOD) model directly to our AGN‐LRG CCF.

We present the analysis of XMM‐Newton spectra of four of the most X‐ray luminous (LX≥1045 erg s−1) radio‐quiet QSOs found in the ROSAT Bright Survey (RBS). We show that objects exhibit surprisingly uniform properties in their X‐ray spectra. All objects show a soft excess and a weak narrow Fe Kα fluorescence line. A self‐consistent disk reflection model is applied to all objects so we can test the current theoretical understanding of complex multi‐component AGN X‐ray spectra.