Granada - X-ray Universe 2008 X-ray selected z>3 QSOs in the XMM-COSMOS field Marcella Brusa (MPE) The XMM-COSMOS and COSMOS teams.. and in particular: A. Comastri, R. Gilli, G. Hasinger, K. Iwasawa, V. Mainieri, M. Mignoli, M. Salvato, G. Zamorani A. Bongiorno, N. Cappelluti, F. Civano, F. Fiore, A. Merloni, J. Silverman, J. Trump, C. Vignali, P. Capak, M. Elvis, O. Ilbert, C. Impey, S. Lilly

Granada - X-ray Universe 2008 Why high-z AGNs are interesting? locally: M BH ~  M Bulge locally: M BH ~  M Bulge SDSS QSO z>6 => M BH ~3-7  10 9 M Sun SDSS QSO z>6 => M BH ~3-7  10 9 M Sun (Willott +03)  Either M~10 12 M Sun bulges are in place at z>6 or the M BH -Bulges-properties relationships must break down at high-z  Either M~10 12 M Sun bulges are in place at z>6 or the M BH -Bulges-properties relationships must break down at high-z  Forming (enough) M Sun BHs and (possibly) M Sun Bulges at z>6 can be a challenge for models of structure formation.  Forming (enough) M Sun BHs and (possibly) M Sun Bulges at z>6 can be a challenge for models of structure formation. As well as forming metals and dust. As well as forming metals and dust. Strong constraints on Strong constraints on cosmological models cosmological models adapted from Ferrarese & Merritt 2000, Gebhardt et al. 2000

Granada - X-ray Universe 2008 X-rays from High-z QSOs : pioneering works with ROSAT Wilkes+92 Elvis+94 Bechtold+94 (record QSO z=4) : Chandra/XMM contribution Follow-up of optically SDSS QSOs Brandt+02 Mathur+02 Vignali+03,05 (record QSO z=6.4) : XEUS … ? record z = 10? Vignali+05

Granada - X-ray Universe 2008 ? The population of z>3 QSO Radio QSO (Wall et al., 2005) Optical QSOs (Schmidt+95, Fan+01,04, Richards+06) Exponential decline in space density at z=2.7 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. 2005/2008)  statistics still low at z~3-5 (NO statistics at z>6) XMM Chandra ROSAT eROSITA XEUS

Granada - X-ray Universe 2008 Cosmos Survey 2 deg 2 (PI: N. Scoville) with deep multiwavelength coverage at all lambda XMM-COSMOS survey (PI: G. Hasinger) Mosaic of 55 XMM observations, 1.4 Ms ~35 ks average One of the main goal: “Characterization of The z>3 QSO population” 1608 soft keV 1103 medium keV 250 hard keV Hasinger+07, Cappelluti+07 See poster by Nico Cappelluti

Granada - X-ray Universe 2008 at S(0.5-2 keV) >1e-15 cgs Predictions: (from XRB models Gilli, Comastri & Hasinger 07) unabs+abs 30 deg-2 (exponential cutoff at z.2.7) Schmidt et al deg-2 (constant evolution extrapolating Hasinger+05 / La Franca+05 LF) z>3 QSO counts: expectations Models from Gilli+07

Granada - X-ray Universe 2008 compilation from ongoing spectroscopic projects [IMACS/Magellan+VLT/ESO + SDSS + literature data] Flux limited sample (50% of the area coverage in at least one band) at cgs 1651 XMM sources <10% problematic ID thanks to IR+Chandra info ~670 “secure” spectroscopic redshifts (40%) Incompleteness especially for high-z and Type 2 AGN XMM-COSMOS sources redshifts (adapted from Brusa et al ApJS) Blue = BL AGN Black = ALL AGN

Granada - X-ray Universe 2008  LESS than 10% catastrophic outliers (to be compared with COMBO-17, Wolf et al. 2004) Photo-z computed using >30 bands: SDSS, Subaru including IB, CFHT, J, K, IRAC.. AGN photometric redshifts Salvato et al. (in prep)

Granada - X-ray Universe 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) Brusa et al. ApJ submitted

Granada - X-ray Universe 2008 QSO2 BALQSO Optical spectra (from VIMOS and IMACS) QSO2?

Granada - X-ray Universe 2008 Photometric redshifts

Granada - X-ray Universe 2008 General properties Magnitude distribution: I=20-26 (25% I>24) Luminosities distribution: Log(Lx) = ACS image, 15”x15” I=23.5

Granada - X-ray Universe 2008 Optical colors Color color selection v-I vs. b-v (proposed, e.g. in Casey et al. 2008, Siana et al. 2007) High-z (>3) locus Interm-z (2-3) Lower-z (0-2) 8 objects would not have been selected ~40 (magenta/yellow) contaminants

Granada - X-ray Universe 2008 X-ray properties  Ratio of obscured/unobscured objects is ~20% logNH<23 logNH>23 logNH<23, BL logNH<23 NOT BL HR vs. redshift

Granada - X-ray Universe 2008 Contribution to source counts Lower bound: 22 spectro-z Upper-bound: adding 10 EXOs Dashed line: Expectations from XRB models extrapolating Hasinger+05 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) Models: Gilli, Comastri & Hasinger 2007, A&A

Granada - X-ray Universe 2008 Space densities Red curve: predictions 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

Granada - X-ray Universe 2008 Summary Results based only on XMM-COSMOS selection and exploitation of COSMOS database (no need to combine with other X-ray surveys… ) Flat evolution at z>3 definitively ruled out (space densities & number counts) 32/40 (80%) X-ray selected quasars would have been selected also by optical color-color criteria (but with a comparable number of low-z contaminants)  not a significant population with unusual optical colors… Sizable sample of obscured AGN (BAL, NL..)

Granada - X-ray Universe 2008 What’s next? High-z quasars:  eROSITA (high-L) ~2500 z>3 QSOs in the “Deep survey”: 400 deg2 on “north+south pole”, F(0.5-2) > 4e-15 cgs ~25000 z>3 QSOs in the All Sky survey: deg2 all sky, F(0.5-2) > 1e-14 cgs  XEUS (low-L and very high-redshift)  joint multiwavelength campaigns Synergies with other (big) observatories is mandatory… - PanSTARRS (all sky) + GROND (for faintest sources) - SDSS-like survey? LAMOST ? - (ESO facilities can be used on 200 deg2 – South pole) - LBT/GTC deep U+Bband imaging (on 200 deg2…) CFHTLS Wide Survey ~100 deg2 (u,g,r,i,z) AB~ CFHTLS Wide Survey ~100 deg2 (u,g,r,i,z) AB~25-26