Granada - X-ray Universe 2008 X-ray selected z>3 QSOs in the XMM-COSMOS field Marcella Brusa (MPE)...

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


Why high-z AGNs are interesting? locally: Mlocally: MBHBH~0.0013~0.0013MMBulge Bulge

SDSS QSO z>6 => MSDSS QSO z>6 => MBHBH~3-7~3-7101099MMSunSun (Willott +03)

Either M~10Either M~101212MMSunSun bulges are in place at z>6 bulges are in place at z>6

or the Mor the MBHBH-Bulges-properties relationships -Bulges-properties relationships must break down at high-zmust break down at high-z

Forming (enough) 10Forming (enough) 109-109-10MMSun Sun BHs and BHs and (possibly) 10(possibly) 101212MMSun Sun Bulges at z>6 can be a Bulges at z>6 can be a challenge for models of structure formation.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 modelscosmological models

adapted from Ferrarese & Merritt 2000, Gebhardt et al. 2000


X-rays from High-z QSOs 1990-1994: pioneering works with ROSAT Wilkes+92Elvis+94 Bechtold+94(record QSO z=4)

2002-2005:Chandra/XMM contributionFollow-up of optically SDSS QSOs Brandt+02Mathur+02 Vignali+03,05 (record QSO z=6.4)

2015-2020:XEUS … ? record z = 10?

Vignali+05


?

The population of z>3 QSORadio QSO (Wall et al., 2005) Optical QSOs (Schmidt+95, Fan+01,04, Richards+06)Exponential decline in space densityat 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)

XMMChandraROSAT

eROSITAXEUS


Cosmos Survey2 deg2 (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 ofThe z>3 QSO population”

1608 soft 0.5-2.0 keV1103 medium 2.0-4.5 keV

250 hard 4.5-10.0 keV

Hasinger+07, Cappelluti+07See poster by Nico Cappelluti


at S(0.5-2 keV) >1e-15 cgs

Predictions: (from XRB models Gilli, Comastri & Hasinger 07)

unabs+abs30 deg-2 (exponential cutoff at z.2.7) Schmidt et al. 1995

80 deg-2 (constant evolution extrapolating Hasinger+05 / La Franca+05 LF)

z>3 QSO counts: expectations

Models fromGilli+07


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 10-15 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. 2007 ApJS)

Blue = BL AGNBlack = ALL AGN


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)


AGN redshift distribution in XMM-COSMOS

X-ray sample (AGN) Empty: specz+photzFilled: 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


QSO2

BALQSO

BALQSO

Optical spectra (from VIMOS and IMACS)

QSO2?


Photometric redshifts


General propertiesMagnitude distribution:I=20-26 (25% I>24)

Luminosities distribution:Log(Lx) = 44 - 45

ACS image, 15”x15”I=23.5


Optical colorsColor 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


X-ray properties

Ratio of obscured/unobscured objects is ~20%

logNH<23

logNH>23

logNH<23, BL

logNH<23NOT BL

HR vs. redshift


Contribution to source countsLower bound: 22 spectro-zUpper-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 outTightest constraints to date (largest and cleanest sample)

Models: Gilli, Comastri & Hasinger 2007, A&A


Space densitiesRed curve: predictionslogLx>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


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..)


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 cgs400 deg2 on “north+south pole”, F(0.5-2) > 4e-15 cgs ~25000 z>3 QSOs in the All Sky survey: 30.000 deg2 all sky, F(0.5-2) > 1e-14 cgs30.000 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~25-26CFHTLS Wide Survey ~100 deg2 (u,g,r,i,z) AB~25-26

Granada - X-ray Universe 2008 X-ray selected z>3 QSOs in the XMM-COSMOS field Marcella Brusa (MPE)...

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