On behalf of the XMM-Newton Survey Science Centre Roberto Della Ceca INAF – Osservatorio Astronomico di Brera,Milan The Cosmological properties of AGN in the XMM-Newton Hard Bright Survey

Co-authors A. Caccianiga (INAF –OABrera, Milan, Italy) P. Severgnini (INAF –OABrera, Milan, Italy) T. Maccacaro (INAF –OABrera, Milan, Italy) H. Brunner (Max Planck, Garching, Germany) F.J. Carrera (IFCA, Santander, Spain) F. Cocchia (INAF-OARoma, Italy) S. Mateos (Leicester University, UK) M.J. Page (MSSL, UK) J.A. Tedds (Leicester University, UK)

Why hard X-ray surveys are important Most direct probe of the SMBH accretion activity SMBH census Constraints to models for the formation and evolution of structures in the Universe

A few key questions…. Which are the cosmological properties (e.g. XLF) of the absorbed and unabsorbed AGN population? Is the ratio absorbed/unabsorbed AGN a function of Lx and/or z? How the results compare with the Unification models of AGN? What about the heavily absorbed (N H >10 24 cm -2 ) Compton Thick AGN?

The XMM Bright Survey is aimed at selecting and spectroscopically identifying a large and statistically representative sample of bright (f x >~7x c.g.s) serendipitous XMM sources in two complementary energy bands keV energy band: Bright Sample (BS) keV energy band: Hard Bright Sample (HBSS) The XMM-Newton Bright Survey

XMM fields used 237 Sources 400 (f x > ~7x cgs) Identified 348 (87%) (~240 sources from us) Covered Area (deg 2 ) 28 Spectroscopic Classification % Type 1 AGN 70% Type 2 AGN 10% Other Extragalactic 4% Stars 16% The XMM-Newton Bright Survey in pills Optical and X-ray spectral analysis is possible for almost all the sources in the XBS!! Della Ceca et al., 2004 Caccianiga et al., 2008

The X-ray sky above 5 keV: the HBSS sample Intrinsic N H vs. Intrinsic L x 67 X-ray src 65 with ID Spectroscopic ID  97% 40 Unabsorbed AGN 22 Absorbed AGN Intrinsic N H N H =4x10 21 Intrinsic Luminosity N H =4x10 21  A v ~2

L x -z plane HBSS Sample Unabsorbed AGN : 40 obj. Absorbed AGN : 22 obj. = 44.2 = 43.7 Redshift Distribution Luminosity Distribution

Absorbed AGN vs. Unabsorbed AGN De-evolved (z=0) X-ray luminosity functions 40 obj 22 obj 4x10 21 <N H <10 24 N H <4x10 21 Absorbed AGN have a steeper XLF than the unabsorbed ones 1/V max method (Schmidt, 1968), correcting for the bias due to the photoelectric absorption.

Fraction of absorbed AGN in the HBS survey Absorbed AGN/All AGN (N H <10 24 cm -2 ) HBSS Beckman et al., 2006 Bassani et al., 2006 Markwardt et al., 2006 Sazonov et al., 2007 Fraction = 0.57  0.11 Abs.AGN (4x1021<N H <10 24 cm -2 ) All AGN (N H <10 24 cm -2 ) L x >3x10 42 erg s -1

Fraction of absorbed AGN in the HBS survey Absorbed AGN/All AGN (N H <10 24 cm -2 ) HBSS Beckman et al., 2006 Bassani et al., 2006 Markwardt et al., 2006 Sazonov et al., 2007 From Integral/Swift E> 10 keV fx> cgs L x >3x10 42 erg s -1 Abs.AGN (4x1021<N H <10 24 cm -2 ) All AGN (N H <10 24 cm -2 ) Very good agreement

Fraction of absorbed AGN vs. Intrinsic Lx From the HBSS sample (z=0) using the best fit XLF In agreement with e.g.: Ueda et al., 2003 La Franca et al., 2005 Akylas et al., 2006 Ballantyne et al., 2006 The fraction of obscured AGN decrease with L x First pointed out by Lawrence and Elvis,1982

From the HBSS sample (z=0) From Akylas et al., 2006 Fraction of absorbed AGN vs. Intrinsic Lx ~0.8 ~1.2 ~1.3 ~1.5 ~2.4 Redshift dependence?

From the HBSS sample (z=0) Rescaled to z=0 using: ~(1+z) 0.4 from (Treister and Urry, 2006, Ballantyne et al., 2006 ) Fraction of obscured AGN vs. Intrinsic Lx The fraction of obscured AGN probably increase with z See also La Franca et al., 2005

Comparison with Unification models The simplest unification scheme of AGN is ruled out HBSS

Comparison with Unification models Standard receding torus model Lawrence (1991) h r torus AGN h r torus AGN

Comparison with Unification models Modified receding torus model h  L  with  =0.23 Simpson (2005); Honig and Beckert (2007)

Comparison with optical samples HBSS Fraction of optically Narrow line AGN Simpson (2005) Compton Thin AND Compton Thick Only Compton Thin AGN

The intrinsic XLF of Compton Thick AGN

XLF Thick = 2 x XLF 4E21-E24

The intrinsic XLF of Compton Thick AGN XLF Thick = 4 x XLF 4E21-E24 XLF Thick = XLF 4E21-E24

The intrinsic XLF of Compton Thick AGN Thick AGN from Sazonov et al., (2007) INTEGRAL keV Sample ID rate = 93%; 4 CT AGN Independent measurements

The intrinsic XLF of Compton Thick AGN Thick AGN from Daddi et al. (2007) rescaled to z=0 (Spitzer+Chandra) data Independent measurements

The intrinsic XLF of Compton Thick AGN Thick AGN from Fiore et al. (2008) rescaled to z=0 (Spitzer+Chandra) data ONE OF THE NEXT TALKS Independent measurements

The intrinsic XLF of Compton Thick AGN Very good agreement with independent X-ray-infrared samples of CT AGN

Compton Thin AGN vs. Compton Thick AGN Compton Thick AGN N H >10 24 cm Compton Thick AGN N H <10 24 cm    0.15 The fraction of CT AGN decrease with L x

Conclusions We have discussed here the HBSS AGN sample. Absorbed AGN have a steeper XLF than the unabsorbed ones; The intrinsic fraction of absorbed (Thin) AGN with L x >~3x10 42 cgs is 0.57  In excellent agreement with local samples of hard (>10 keV) selected AGN at a flux limit of cgs; The fraction of abs. AGN is a function of L x and, probably, of z; Our results support the modified receding torus model; We have derived, in an indirect way, the XLF of Compton Thick AGN and found that XLF Thick ~ 2 x XLF 4E21-E24 ; The fraction Thick AGN/Thin AGN decreases with L x.

The projects presented here have received partial financial support from ASI, MIUR and INAF grants over the last few years. THANKS Astro-ph/