INTEGRAL/IBIS Extragalactic survey: 20-100 keV selected AGN

Analysis of INTEGRAL Core Program and public Open Time observations performed up to April 2005 provides a sample of 62 active galactic nuclei in the 20-100 keV band above a flux limit of ∼ 1.5×10 erg cm s. Most(42) of the sources in the sample are Seyfert galaxies, almost equally divided between type 1 and 2 objects, 6 are blazars and 14 are still unclassified. Excluding the blazars, the average redshift of our sample is 0.021 while the mean luminosity is Log(L) = 43.45. We find that absorption is present in 65% of the objects with 14% of the total sample due to Compton thick active galaxies. In agreement with both Swift/BAT team results and 2-10 keV studies, the fraction of absorbed objects decreases with the 20-100 keV luminosity. All Seyfert 2s in our sample are absorbed as are 33% of Seyfert 1s. The present data highlight the capability of INTEGRAL to probe the extragalactic gamma-ray sky and to find new and/or absorbed active galaxies. Subject headings: surveys — galaxies: active — gamma rays: observations Based on observations obtained with the ESA science mission INTEGRAL IASF-Bologna/INAF, via P. Gobetti 101, 40129 Bologna, Italy; [email protected], [email protected], [email protected] School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, UK; [email protected], [email protected], [email protected] IASF-Roma/INAF, via del Fosso del Cavaliere 100, I-00133 Roma, Italy; [email protected], [email protected], [email protected] CEA Saclay/DSM/DAPNIA/Sap, 91191 Gif Sur Yvette, France; [email protected], [email protected], [email protected] INTEGRAL Science Data Center, Chemin D’Écogia 16, 1290 Versoix, Switzerland; [email protected]