Statistics of relativistically broadened Fe K α lines in AGN

We present preliminary results on the properties of relativistically broadened Fe K α lines in a collection of more then 100 Active Galactic Nuclei (AGN) observed by the XMM‐Newton EPIC‐pn camera. Our main conclusions can be summarized as follows: a) we detect broad lines in about 25% of the sample objects. This fraction increases to 42 ± 13% if we consider only objects with more than 10 4 counts in the hard (2–10 keV) band, and to 50 ± 32% for the small sub‐sample (6 objects) of type 1 Piccinotti AGN with optimal XMM‐Newton exposure (at least 2 × 10 5 counts in the hard band); b) we find no significant difference in the detection rate of broad lines between obscured and unobscured AGN; c) the strongest relativistic profiles are measured in low‐luminosity ( L X < 10 43 erg s –1 ) AGN; d) Equivalent Widths (EWs) associated with relativistic profiles in stacked spectra are ≲150 eV for all luminosity classes; e) models of relativistically broadened iron line profiles (kyrline, Dovčiak et al. 2005), which include full relativistic treatment of the accretion disk emission around a Kerr black hole in the strong gravity regime, yield an average disk inclination angle ≃30°, and a radial dependence of the disk emissivity profile ≃–3. The distribution of EW is very broad, with 〈log (EW)〉 = 2.4 and σ log (EW) = 1.4. We estimate that an investment of about 1 Ms of XMM‐Newton time would be required to put these results on a sound statistical basis. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)