HST Workshop Bologna Jan 31, 2008

Heavily obscured Heavily obscured SMBH at high SMBH at high redshiftredshiftAndrea ComastriINAF - 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,

P. Tozzi, I. Georgantopoulos

HST Workshop Bologna Jan 31, 2008

OutlineAccreting 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 SM4 (WFC3 - IR channel) Host galaxies morphologies - high z (> 6) obscured QSO

HST Workshop Bologna Jan 31, 2008

AGN and galaxy co-AGN and galaxy co-evolutionevolution

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

AGN hosts (mostly early type morphology) populate the red sequence and green valley

AGN activity persist after SF has ended Many hard sources in the red sequence At variance with model predictions

Mignoli+04HELLAS2XMM

Pozzi+07 See also Silverman+07AGN hosts in the green valley

HST Workshop Bologna Jan 31, 2008

Evidences for missing SMBH

Marconi+04/08

Gilli, AC, Hasinger 07

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 X-rays and in the MIR (thanks to the reprocessing of the nuclear radiation by dust)

HST Workshop Bologna Jan 31, 2008

135 sources (out of 1729 with F24 > 40 Jy) 22 detected by Chandra <LX>=43.4+/-0.3, <NH>=22.9+/-0.8, <z>~2.1 LogF(1.5-4keV) stacked sources= -- 17 @z~2 logLobs(2-8keV) stacked sources ~41.8 log<L (6 m) > ~ 44.6 ==> logL(2-8keV) unabs.~43 Difference implies logNH > 24 Fiore+08

“Mildly” CT AGN Absorption by CT gasmay be key ingredientof feedback mechanism

Daddi+07

IR-optical

HST Workshop Bologna Jan 31, 2008

CT AGN onlybarely sampledby deep Chandra and XMM surveys

Relative fraction steeply increasing

Hard (> 10 keV) surveys more efficient

Redshift distribution <z> ~ 0 @ 10-11

<z> ~ 1 @ 10-15

X-ray

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

Rodighiero+07

Brusa, Fiore+08 Koekemoer+04EXOsCandidate z > 6More likely z~2-3

HST Workshop Bologna Jan 31, 2008

Host galaxy morphologies

ACS cutoutsof two Type 2AGN in the z ~ 0.7CDFS LSSType 2 AGN at higher redshiftBrusa,Fiore+08

•Koekemoer+02

•Grogin+03

•Schreier+01

HST Workshop Bologna Jan 31, 2008

K

K-band (ISAAC@VLT) residuals after deconvolution without and with the central component

Z ~ 0.1 - 0.2 !!!

Galaxy:J=16.52±0.01K=15.25±0.01AGN:J=20.30±0.35K=18.09±0.10

Galaxy:J=16.92±0.05K=15.21±0.01AGN:J=20.75±0.29K=18.39±0.24

K

Host galaxy morphologies

Civano+07

More than 100 obscured AGN (a few tens CT) will be discovered by XMM & Chandra ultra-deep CDFS surveys

WFC3 - IR deep (AB ~ 28) high resolution observations

Obscured AGN host galaxy morphologiesPick 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 ?

Summary