1. Evolution of Supermassive Black Holes from deep & large area X-ray surveys Marcella Brusa (Max Planck Institut fuer Extraterrestrische Physik)

2. AGN 8 - Torino, May 2008 Outline Introduction: AGN evolution What we know: observations & models Still missing (among others..):  high-redshift population  Compton Thick AGN census Summary & future

3. AGN 8 - Torino, May 2008 Main actors in this game XMM/Chandra COSMOS teams CDFS/GOODS/MUSIC team ELAIS-S1 team HELLAS2XMM team.. and in particular thanks to: A.Comastri, F.Fiore, R.Gilli, A.Bongiorno, N.Cappelluti, F.Civano, G.Hasinger, K. Iwasawa, V. Mainieri, A. Merloni, M. Mignoli, S.Puccetti, M.Salvato, C. Vignali, G.Zamorani, C.Feruglio, A.Grazian, F.LaFranca, F.Pozzi, P.Santini…

4. AGN 8 - Torino, May 2008 introduction AGN evolution Once upon a time… (1960s-70s): QSO/AGN are triggered by accretion on SMBH QSO/AGN are 1% of galaxy population:  transient phase or rare objects? [45 years of observations] Nowadays: SMBH can be revealed in almost 100% of local galaxies AGN transient phase!

5. AGN 8 - Torino, May 2008 MAIN OBSERVATIONAL RESULT: The discovery of dead SMBH in most local bulges & tight correlation between M BH and bulge properties Co-evolution of galaxies and SMBH  Large scale Galaxy properties strongly depend on BH mass Ferrarese & Merritt 2000 Gebhardt et al. 2000 Marconi & Hunt 2003

6. AGN 8 - Torino, May 2008 AGN and galaxy co-evolution Early on Strong galaxy interactions; Mergers between gas rich galaxies drive gas which fuel both SF and BH activity; Violent starbursts episodes; Heavily obscured BH growth When galaxies coalesce A ccretion peaks; SMBH becomes optically “visible” (QSO phase) as AGN winds blow out gas Later times SF & BH accretion quenched; Dead quasars (or slowly accreting BH) in red galaxies (passive evolution) [see also Granato+2004, Di Matteo, Springel & Hernquist 05, Hopkins+07] Li et al. 2007 To prove this scenario we need: 1)Complete SMBH census, 2)Physical models for AGN feedbacks 3)Observational constraints to these models Li et al. 2007

7. AGN 8 - Torino, May 2008 How to study AGN evolution? Count and detect AGN at different phase/stages of their evolution  Surveys Accretion Luminosity is emitted over a broad range of wavelengths, BUT the X-ray emission is the AGN footprint  X-ray surveys AGN come in 2 flavours: unobscured and obscured,obscuration affects mostly the soft X-ray and optical wavelengths  Hard (>2 keV) X-ray surveys (unbiased) Multiwavelength follow-up (redshifts!)

8. AGN 8 - Torino, May 2008 Evolution of Obscured AGN – why bother? (1) XRB fit Gilli, Comastri, Hasinger 07 Red -> unobscured AGN Blue + Black -> obscured AGN Obscured AGN are needed to reproduce the XRB peak [e.g. Setti & Woltjer 1989 ……. Gilli, Comastri & Hasinger 2007]

9. AGN 8 - Torino, May 2008 IF all galaxies undergo an AGN phase and IF dead SMBH observed today are the remnants/witnesses of this phase  The BH mass density obtained integrating the luminosity emitted by AGN over the cosmic time is expected to be similar to that measured in local bulges  Soltan’s argument: mass accreted is equal to the energy released (E = mc 2 …) (Soltan 1982) ρ(direct) ~ ρ ● ~ 3-5.5 x 10 5 M ⊙ Mpc -3 [see e.g. Shankar et al. 2008 Marconi et al. 2004, Fabian 2003, Fabian & Iwasawa 1999 etc] Evolution of Obscured AGN – why bother? (2) BH growth INCLUDING ALSO OBSCURED / CT AGN

10. AGN 8 - Torino, May 2008 XMM-COSMOS 2 deg2 -16 -15 -14 -13 Flux 2-10 keV (cgs) CDFN-CDFS 0.1deg2 Barger et al. 2003; Szokoly et al. 2004 EGS/AEGIS 0.5deg2 Nandra et al. 2006 HELLAS2XMM 1.4 deg2 Fiore et al. 20003 Cocchia et al. 2006 Champ 1.5deg2 Silverman et al. 2005 XMM HBS ~25 deg2 Della Ceca+04,08 XBOOTES 9 deg2 Murray et al. 2005, Brand et al. 2005 Survey of surveys - X-rays + multiwave SEXSI 2 deg2 Eckart et al. 2006 Area (see Brandt & Hasinger 2005 ARA&A 43, 827) E-CDFS 0.3deg2 Lehmer et al. 2005 ELAIS-S1 0.5deg2 Puccetti et al. 06, Feruglio et al. 08 Lockman Hole 0.2 deg2 Brunner et al. 2008 Contiguous C-COSMOS 0.9 deg2

11. AGN 8 - Torino, May 2008  picture quite clear from optical/soft/hard X-ray surveys: Luminosity-Dependent Density Evolution (LDDE) [see also Ueda+03, Cirasuolo+05, Della Ceca+08]  Anti-hierarchical growth/Downsizing [Cowie et al. 1996, Merloni 2004, De Lucia et al. 2006] Evolution Fiore +03 La Franca +05 Hasinger+05 Bongiorno+07

12. AGN 8 - Torino, May 2008 Fraction of absorbed sources: Luminosity dependence  fraction of obscured AGN is a strong function of L: most luminous, less obscured  Same result in DIFFERENT bands despite the very different selections!! Hasinger et al. 2005 (see also La Franca +05, Treister+05, Della Ceca+08) Black: X-ray Hasinger 2008 Green: IR Maiolino et al. 2007 Red: Optical Simpson et al. 2005

13. AGN 8 - Torino, May 2008 Fraction of absorbed sources: Redshift dependence  more debated! Seen in (some) data [e.g. La Franca+05, Treister+06, Hasinger08], not seen in others (Ueda+03, Dwelly&Page 2006), not needed in XRB models (Gilli+07) but expected/predicted in feedback models (Menci+08) La Franca +05 Hasinger 2008

14. AGN 8 - Torino, May 2008 Still missing (open problems) Compton Thick objects / census number density and evolution of high-z population (z>3) Interplay between AGN and SF / feedback models [see Marulli/Fontanot] Bolometric output/reprocessing [see Severgnini/Bellocchi/Lusso] BH mass / accretion rate evolution [see Labita] Elusive AGN (e.g. XBONGs/EXOs) [see Civano/Del Moro/Lanzuisi] Role of the envinronment in triggering nuclear activity [e.g. results from AEGIS/Groth strip – Georgakakis+07,08]

15. AGN 8 - Torino, May 2008 The population of z>3 QSOs (XMM-COSMOS) Brusa, Comastri, Gilli et al. 2008, ApJ, submitted

16. AGN 8 - Torino, May 2008 ? The population of z>3 QSO Radio QSO (Wall et al., 2005) Optical QSOs (Schmidt et al., 1995, Fan et al. 2001,2004) X-ray: What happens at z>3? decline or ~costant ? Soft X-ray ROSAT/Chandra/ XMM (Hasinger, Miyaji & Schmidt 2005) Chandra/ROSAT (Silverman et al. 2005/2007) statistics still low at z~3-5 (NO statistics at z>6) COSMOS

17. AGN 8 - Torino, May 2008 + MAMBO, CFHT, Bolocam and (future) others COSMOS major components (in order of appearance) : HST/ACS (I-band – 590 orbits – I(AB)~27) 2002-2003: Subaru imaging (~25 nights - b,v,r,i,z=26/27) VLA (265 hours – 24 μJy) GALEX deep (200 ks, AB~25) XMM-Newton (800 ks – 10 -15 cgs) 2004-2005: XMM-Newton (600 ks) VLT (540 hours) & Magellan (12+ nights) SPITZER-IRAC (200 hours - ~1 μJy) 2006: SPITZER-MIPS (200 hours - ~70 μJy ) Chandra (1.8 Ms) Cosmos Survey 2 deg 2 (PI: N. Scoville) >150 team members worldwide! http://www.astro.caltech.edu/cosmos/ XMM-Newton PI: G. Hasinger Hasinger et al. 2007 soft 0.5-2.0 keV medium 2.0-4.5 keV hard 4.5-10.0 keV http://cosmos.astro.caltech.edu ApJS special issue vol. 172 (>550 pages!)

18. AGN 8 - Torino, May 2008 AGN redshift distribution in XMM-COSMOS X-ray sample (AGN) Empty: specz+photz Filled: specz Sources extracted from a flux limited sample in XMM-COSMOS (50% of the area coverage in at least one band) 1651 XMM sources - 10% problematic ID using IR+Chandra info ~670 “secure” spectroscopic redshifts (40%), incompleteness especially for high-z and Type 2 AGN Accurate photometric redshifts available (Salvato et al. 2008)

19. AGN 8 - Torino, May 2008  LESS than 10% catastrophic outliers (to be compared with COMBO-17, Wolf et al. 2004) 434 objects with “super-secure” spectro-z (further refinement/analysis) Photo-z computed using >30 bands: SDSS, Subaru including IB, CFHT, J, K, IRAC.. AGN photometric redshifts Salvato et al. (in prep)

20. AGN 8 - Torino, May 2008 AGN redshift distribution in XMM-COSMOS X-ray sample (AGN) Empty: specz+photz Filled: specz z>3 sample: 40 objects (22 specz + 18 photoz) Additional 14 objects, no photoz available. Candidates very high-z AGN (EXOs, Koekemoer et al. 2004) Sources extracted from a flux limited sample in XMM-COSMOS (50% of the area coverage in at least one band) 1651 XMM sources - 10% problematic ID using IR+Chandra info ~670 “secure” spectroscopic redshifts (40%), incompleteness especially for high-z and Type 2 AGN Accurate photometric redshifts available (Salvato et al. 2008)

21. AGN 8 - Torino, May 2008 Examples of images, spectra & photoz B g v r I z IRAC 3.6 XID 54439 z=4.241

22. AGN 8 - Torino, May 2008 X-ray properties HR vs. redshift  Ratio of obscured/ unobscured objects in agreement with XRB models

23. AGN 8 - Torino, May 2008 Contribution to source counts Lower bound: 22 spectro-z Upper-bound: adding 10 EXOs Dashed line: Expectations from XRB models using Hasinger et al. 2005 LF Solid line: Exponential decay introduced at z=2.7 (Schmidt+95) Flat evolution completely ruled out Tightest constraints to date (largest and cleanest sample) z>4 point : Rhook & Haenelt 08 predict a factor of ~3 higher wrt data Models: Gilli, Comastri & Hasinger 2007, A&A

24. AGN 8 - Torino, May 2008 Space densities Red curve: predictions from XRB models logLx>44.2 AGN (unobs+obs) [Gilli+07 using Hasinger+05 and La Franca+05] Dashed area: (rescaled) space density for optically selected bright QSO [Richards+2006, Fan+2001] Blue curve: Silverman+08 LF, I<24 sample

25. AGN 8 - Torino, May 2008 The census of z~1-3 CT AGN/QSOs (CDFS+COSMOS) Fiore et al. 2008a, ApJ, 672, 94 Fiore, Puccetti, Brusa et al. 2008b, ApJ, submitted

26. AGN 8 - Torino, May 2008 Unveiling obscured accretion X-ray surveys : miss most highly obscured (Compton Thick) AGN [e.g. Comastri 2004, Worsley et al. 2005] IR surveys : highly obscured AGN shine in the MIR – dust reprocessing [e.g. Martinez-Sansigre et al. 2005, Polletta et al. 2006] Goal: combining X-ray and IR surveys to get the SMBH census and compile AGN bolometric LF X-ray-MIR surveys: CDFS/GOODS/MUSIC [Grazian et al. 2006, Brusa et al. in prep, CDFS team papers] ELAIS-S1/SWIRE [Feruglio et al. 2008, La Franca et al. 2008] COSMOS [XMM-COSMOS: Brusa et al. 2008; + C-COSMOS/S-COSMOS papers] X-ray surveys : miss most highly obscured (Compton Thick) AGN [e.g. Comastri 2004, Worsley et al. 2005] IR surveys : highly obscured AGN shine in the MIR – dust reprocessing [e.g. Martinez-Sansigre et al. 2005, Polletta et al. 2006] Goal: combining X-ray and IR surveys to get the SMBH census and compile AGN bolometric LF X-ray-MIR surveys: CDFS/GOODS/MUSIC [Grazian et al. 2006, Brusa et al. in prep, CDFS team papers] ELAIS-S1/SWIRE [Feruglio et al. 2008, La Franca et al. 2008] COSMOS [XMM-COSMOS: Brusa et al. 2008; + C-COSMOS/S-COSMOS papers]

27. AGN 8 - Torino, May 2008 All sources BL AGN NOT BL AGN High MIR/O MIR selection of CT AGN XMM-COSMOS sample HR distribution [Brusa et al. 2008b] See also results from ELAIS-S1, Feruglio et al. 2008, Lanzuisi’s talk Select candidate, luminous obscured AGN by imposing: 24 micron bright fluxes (luminous) + optically faint red sources (optically obscured) high MIR/O ratio Select candidate, luminous obscured AGN by imposing: 24 micron bright fluxes (luminous) + optically faint red sources (optically obscured) high MIR/O ratio

28. AGN 8 - Torino, May 2008 Combining MIR/O and R-K criteria: selection of CT AGN at z~2 Fiore et al. 2008a See also Daddi et al. 2007 GOODS CDFS field (1 Ms Chandra data) + MUSIC MW catalog (Spitzer+HST+VLT) ~110 obscured AGN candidates Stack of Chandra images excluding X-ray detections in two different MIR/O and R-K bins Tracks of obscured AGN [Pozzi et al 2007]

29. AGN 8 - Torino, May 2008 A new population of CT AGN Curves: model predictions from Gilli, Comastri & Hasinger (2007) for L> 42, 43, 44, 45 Daddi et al. 2007 Fiore et al. 2008 Martinez-Sansigre et al. 2005 Polletta et al. 2006 The observed MIR luminosity and the observed HR imply (unobs) Lx>43 and NH>24 for ~80% of the sources Low R-K or

30. AGN 8 - Torino, May 2008 COSMOS MIR AGN Fiore et al. 2008b  High AGN fraction (~65%) in MIPS selected samples (deeper X-ray data + more comprehensive analysis)

31. AGN 8 - Torino, May 2008 Summary The fraction of obscured sources depend strongly on luminosity The fraction of obscured sources evolves (increases) with redshift Flat evolution at z>3 definitively ruled out (space densities & number counts) Significant population of CT QSO at z~2 detected

32. AGN 8 - Torino, May 2008 What’s next? Compton Thick AGN/quasars:  XMM ultra deep 1.3 Ms (this fall)  exploit stacking… (Chandra 2 Ms)  Simbol-X (high-energy)  Herschel (reprocessing) High-z quasars:  eROSITA (high-L)  XEUS (low-L and very high-redshift)  joint multiwavelength campaigns