AAS 207th Meeting, 8-12 January 2006
Session 51 Highlights and Discoveries from INTEGRAL
Special Session, Monday, 2:30-4:00pm, January 9, 2006, Delaware A

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[51.04] INTEGRAL Studies of Active Galactic Nuclei

V. Beckmann, N. Gehrels, C. R. Shrader (NASA GSFC), S. Soldi (INTEGRAL Science Data Centre, Switzerland)

We present the first INTEGRAL AGN catalog, based on observations performed from launch of the mission in October 2002 until January 2004. The catalog includes 42 AGN, of which 10 are Seyfert 1, 17 are Seyfert 2, and 9 are intermediate Seyfert 1.5. The fraction of blazars is rather small with 5 detected objects, and only one galaxy cluster and no star-burst galaxies have been detected so far. A complete subset consists of 32 AGN with a significance limit of 7 sigma in the INTEGRAL/ISGRI 20-40 keV data. Although the sample is not flux limited, the distribution of sources shows a ratio of obscured (NH > 1022 cm-2) to unobscured AGN of 1.5 - 2.0, consistent with luminosity dependent unified models for AGN. Only 4 Compton thick AGN are found in this low redshift (z = 0.02), low luminosity (LX = 2 x 1043 erg s-1) sample. Based on the INTEGRAL data presented here, the Seyfert 2 spectra are slightly harder (Gamma = 1.95 ±0.01) than Seyfert 1.5 (Gamma = 2.10 ±0.02) and Seyfert 1 (Gamma = 2.11 ±0.05). INTEGRAL studied also a number of AGN in greater detail in the 2 - 500 keV energy range, including sources like Cen A, NGC 4151, 3C 273, Circinus galaxy, and NGC 4388. These studies probe the role of Compton reflection in AGN.

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Bulletin of the American Astronomical Society, 37 #4
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