Heavily obscured SMBH at high redshift Andrea Comastri

Heavily obscured SMBH at high redshift Andrea Comastri INAF - OABologna C. Vignali, R. Gilli, K. Iwasawa, F. Civano, M. Brusa, N. Cappelluti, , F. Fiore, G. Zamorani, W. N. Brandt, X. Barcons, F. Carrera, F. Nicastro, V. Mainieri, H. Brunner, A. Merloni, J. Silverman, P. Rosati, S. Puccetti, Tozzi, I. Georgantopoulos HST Workshop Bologna Jan 31, P. 2008

Outline Accreting SMBH represents a key ingredient of AGN/galaxy formation and co-evolution. AGN census and evolution (the search for the most obscured -Compton Thick- ones) The Ultradeep XMM - CDFS survey add spectral sensitivity to multi data HST after SM 4 (WFC 3 - IR channel) Host galaxies morphologies - high z (> 6) obscured QSO HST Workshop Bologna Jan 31, 2008

AGN and galaxy co-evolution § Early on § Strong galaxy interactions= violent star-bursts § Heavily obscured QSOs § When galaxies coalesce § accretion peaks § QSO becomes optically visible as AGN winds blow out gas. § Later times § SF & accretion quenched § red spheroid, passive evolution Most BH mass accreted during luminous AGN phases ! Most bulges passed a phase of activity HST Workshop Bologna Jan 31, 2008

Mignoli+04 HELLAS 2 XMM AGN hosts (mostly early type morphology) populate the red sequence and green valley Pozzi+07 AGN activity persist after SF has ended See also Silverman+07 Many hard sources in the red sequence At variance with model predictions AGN in the green valley HST Workshop Bologna Jan 31, hosts 2008

Evidences for missing SMBH Gilli, AC, Hasinger 07 Marconi+04/08 Compton Thick AGN are predicted to be as numerous as unobscured and less obscured AGN HST Workshop Bologna Jan 31, 2008

Highly obscured AGN highly obscured at optical and soft X-ray wavelengths shine in hard Xrays and in the MIR (thanks to the reprocessing of the nuclear radiation by dust) HST Workshop Bologna Jan 31, 2008

IR-optical “Mildly” CT AGN Absorption by CT gas may be key ingredient of feedback mechanism Daddi+07 § § § § 135 sources (out of 1729 with F 24 > 40 Jy) 22 detected by Chandra <LX>=43. 4+/-0. 3, <NH>=22. 9+/-0. 8, <z>~2. 1 Log. F(1. 5 -4 ke. V) stacked sources= -- 17 @z~2 log. Lobs(2 -8 ke. V) stacked sources ~41. 8 log<L (6 m) > ~ 44. 6 ==> log. L(2 -8 ke. V) unabs. ~43 Difference implies log. NH > 24 Fiore+08 HST Workshop Bologna Jan 31, 2008

X-ray CT AGN only barely sampled by deep Chandra and XMM surveys Relative fraction steeply increasing Hard (> 10 ke. V) surveys more efficient Redshift distribution <z> ~ 0 @ 10 -11 <z> ~ 1 @ 10 -15 HST Workshop Bologna Jan 31, 2008

XMM Ultradeep field XMM simulation ~ 370 ks already available ~ 1. 3 Ms in 2008 Aim at 3 Ms Chandra 2 Ms just completed (PI W. N. Brandt) Aim at 4 -5 Ms HST Workshop Bologna Jan 31, 2008

Optically faint/Undetected Brusa, Fiore+08 Koekemoer+04 EXOs Candidate z > 6 More likely z~2 -3 Rodighiero+07 HST Workshop Bologna Jan 31, 2008

Host galaxy morphologies ACS cutouts of two Type 2 AGN in the z ~ 0. 7 CDFS LSS Type 2 AGN at higher redshift Brusa, Fiore+08 • Koekemoer+02 • Grogin+03 HST Workshop Bologna Jan 31, 2008 • Schreier+01

Host galaxy morphologies Galaxy: J=16. 52± 0. 01 K=15. 25± 0. 01 AGN: J=20. 30± 0. 35 K=18. 09± 0. 10 K K-band (ISAAC@VLT) residuals after deconvolution without and with the central component Z ~ 0. 1 - 0. 2 !!! K HST Workshop Bologna Jan 31, 2008 Civano+07 Galaxy: J=16. 92± 0. 05 K=15. 21± 0. 01 AGN: J=20. 75± 0. 29 K=18. 39± 0. 24

Summary More than 100 obscured AGN (a few tens CT) will be discovered by XMM & Chandra ultra-deep CDFS surveys WFC 3 - IR deep (AB ~ 28) high resolution observations Obscured AGN host galaxy morphologies Pick up faint red nuclei Red passive galaxy hosting dying SMBH ? The role of environment (i. e. LSS @ z ~ 0. 7) Is AGN feedback responsible of SF quenching ? Very faint or undetected --> very high-z AGN ? HST Workshop Bologna Jan 31, 2008