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Castel Gandolfo, Ottobre 2005 Agn and Galaxy Evolution. AGN and Galaxy evolution from Deep X-ray surveys: latest results from the CDFS. Paolo Tozzi. Deep X-ray Surveys: open issues. The unresolved fraction of the XRB at high energies, and its relation with obscured cosmic matter accretion
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Castel Gandolfo, Ottobre 2005 Agn and Galaxy Evolution AGN and Galaxy evolution from Deep X-ray surveys: latest results from the CDFS Paolo Tozzi
Deep X-ray Surveys: open issues The unresolved fraction of the XRB at high energies, and its relation with obscured cosmic matter accretion The two epochs of cosmic accretion X-ray properties of optically or radio selected sources: star formation at high z Effects of Large Scale Structure on AGN activity
0.3-1 keV 1-3 keV 3-7 keV Rosati et al. 2002 National Geographic, Dec 2002
AGN Contribution to the hard XRB Beppo SAXVecchi et al. 1999 ASCA2Ishisaki et al. 1999 ASCA1Ueda et al. 1999 HEAO1 Marshall et al. 1980 90% resolved in 0.5-2 keV 93% resolved in 2-8 keV AGN contribution 83% in 0.5-2 keV 95% in 2-8 keV (Bauer et al. 2004) CDFS (1Ms): XRB(S> 4.5×10 -16) = (1.70±0.15)×10 -11 erg s -1cm -2deg -2 CDFN (2Ms): XRB(S> 2 ×10 -16) = (2.07±0.15)×10 -11 erg s -1cm -2deg -2
The unresolved fraction increases with the energy band ~50% not resolved yet for E> 5 keV (Worsley et al. 2004, 2005) Missing XRB: NH=4.5 1023 cm-2 @ z=0.8 Worsley et al. 2004; 2005
Detected fraction as a function of NH and z z < 0.7 0.7 < z <1.5 z > 1.5 Sampling different luminosities and spectral population at different z
NH histogram corrected for completeness The NH distribution tells us about the fraction of the sky seen from the black hole covered by a given column density Tozzi et al. 2005 Tozzi et al. 2004
Whole sample (321) QSOII (44) Whole sample (321) Cthick candidates (14) Consistent with evolutionary sequence: pre-QSO phase C-thin absorbed QSO (QSOII @ high z) unobscured QSO activity quiescent spheroidal galaxy Alexander et al. 2005; Stevens et al. 2005 Model: Granato et al. 2005 Part of the missing XRB is from intermediate z strongly absorbed moderate luminosity, possibly C-thick sources, in a secondary, relatively low-z phase of accretion (see “downsizing” or anti- hierarchical behaviour)
Luminosity dependent density evolution: downsizing or anti-hierarchical behaviour Ueda et al 2003 Hasinger et al. 2005
Merloni 2005 It is crucial to understand the properties of accretion through a careful analysis of the X-ray emission properties (luminosity, intrinsic absorption and its dependence on luminosity and redshift)
Worsley et al. 2004 This work After computing the skycoverage according to the spectral shape of each source
Submm detection of a Type II QSO Mainieri et al. 2004 As expected in the starburst/BH model (Fabian 1999)
Use secure spectral identifications in CDFS and CDFN 29 galaxies with good spectra in the CDFS and emission line ratios consistent with starbursts or normal galaxies give the X-ray priors. A Bayesian approach allows us to identify 74 galaxies in the CDFS and 136 in the CDFN (2 Ms) Norman et al. 2004
SFR densities XLF consistent with a PLE ~ (1+z)2.7 Consistent with an evolution of SFR Q(1+z)2.7 for 0<z<1. Compilation from Tresse et al. 2002: Gallego et al. 1995 (H ) Gronwall 1999 Hopkins et al. 2000 Pascual et al. 2001 Tresse et al. 2002 Sullivan et al. 2000 Lilly et al. 1996 Lines from 60 m Saunders et al. 1990, Takeuchi et al. 2003 Norman et al. 2004 XLF of Star Forming Galaxies is a goal for future X-ray missions (Con-X, XEUS)
K20 survey Daddi et al. 2004
IR selected galaxies at z~2 with massive SF Soft Hard Stacked image of 23 BzK galaxies; HR< -0.5 @ 2sigma ; L2-10~1042 erg/sec SFR ~ 170 MA yr-1 (4 higher than LBG). SFRD of 0.04 MA /yr/Mpc3 We are witnessing the massive spheroid formation epoch (the peak of just the low-z tail?) Daddi et al. 2004
Extended CDFS PI N. Brandt ~1000 sources (Lehmer et al. 2005) 1Ms + 4 X 240 ks
Radio Catalog 236 sources on ~ the same ECDFS area Match Radio Sources with 366+644 sources in the 1Ms+ECDFS(new only) Combined X-ray images of all the remaining radio sources With K. Kellerman, Ed Fomalont, J. Kelly, P. Shaver, & the CDFS Team.
X-ray Radio matches: 48 sources (out of 366 in the 1Msec catalog) 83 sources (in the 1Ms+EXT cat) 45 sources have: spectroscopic redshift and optical type (27) photometric redshift (18) soft and hard band luminosity Intrinsic absorption, spectral shape 160 Radio sources without X-ray counterpart But with sub-treshold X-ray emission: 83 within the 1Ms+ECDFS exposure +77 within the ECDFS (only 240 ks)
LR-LX correlation for sources with X-ray detection for 45 sources with z (luminosity from best fit X-ray model) (soft hard) 13 sources with LX<1042 erg s-1 8 LEX 2 HEX 3 non id
Distribution of intrinsic NH Distribution of intrinsic absorption for 45 sources with spec or photometric z, compared with the distribution of the whole X-ray sample 17 sources with high LR 28 sources with low LR NH>1022 cm-2 ~ Type II AGN 1021 < NH < 1022 cm-2 ~ Type I AGN NH<1021 cm-2 ~ Type I AGN – SF Gal
X-ray photometry for the remaining Radio sources Photometry for the 83 sources within the 1Ms field detected only in the radio: 485 +- 80 soft (0.5-2 keV) 260 +- 80 hard (2-7 keV)
Large Scale structures in CDFS AGN and Early Type galaxies (from K20 survey, Cimatti et al. 2002) are tracing the same structures. Weak hints for enhanced X-ray activity in large scale structures. X-ray to K-band number ratio is 0.33±0.07 in the field 0.36±0.10 at z=0.73 0.7±10.22 z=0.67 Gilli et al. 2003
Γ = 1.33 ± 0.11 r0 = 8.6 ± 1.2 h-1 Mpc CDFS r0 = 4.2 ± 0.4 h-1 Mpc CDFN consistent with that of early type galaxies Gilli et al. 2004
Extended CDFS COSMOS XMM Hasinger et al. 2006 Lehmer et al. 2005 2 deg2, 25 pointings, 60 ksec each 0.3 deg2, 4 pointings, 250 ksec each Other wide X-ray surveys: Bootes (9 deg2); ELAIS (1 deg2) Prospects for the current X-ray surveys
COSMOS area galaxy formation simulation : gas red – yellow stars blue credit : Takeda 4D2U/NOAJ -- Saitoh & Koda
Expected clustering significance Credits to R. Gilli
CONCLUSIONS • Hard XRB resolved at 90 % level at fluxes S ~ 2×10-16 below 5 keV (but ~50% @5 keV: the energy density of the XRB peaks at 30 keV) • A hard, faint population still to be discovered (possibly Compton thick sources detectable in submm with SCUBA/Spitzer) • Part of this “missing population can be already in the faintest part of the X-ray sources population • Towards an universal distribution of intrinsic absorption • Evidence for strongly absorbed, C-thick sources @ z~1, and a substantial QSOII population at z>~2 • >~80% of the AGNs agree with simple unification models. • X-ray Emission from Normal Galaxies: SFR up to z~1; Star forming massive galaxies at z~2 seen in X-ray • Mild effect of the Large Scale structures on nuclear activity, but larger efforts under way
X-ray spectral analysis Galactic absorption Power law + intrinsic absorption + Gaussian line @ 6.4 /(1+z) keV + scattered component unabsorbed power law (same slope)
Synthesis Models for the Cosmic XRB (Setti & Woltjer 1989, Madau, Ghisellini & Fabian 1994, Comastri et al. 1995, Gilli, Salvati & Hasinger 2001) were built on the following assumptions: The Cosmic X-ray Background is largely due to accretion onto supermassive black holes integrated over cosmic time. The X-ray observations are consistent with a mixture of absorbed and unabsorbed AGN, folded with the corresponding luminosity function and cosmological evolution. Most of the AGN spectra are heavily absorbed, and ~ 80% of the light produced by accretion is absorbed by gas and dust (in the nuclear starburst region that feeds the AGN).
Obscured fraction vs L Tozzi et al. 2005 Ueda et al. 2003
The XRB is the echo of the formation of Massive Black Holes through the history of the Universe ROSAT and ASCA resolved most of the Soft XRB. The spectral index of AGNs detected with ROSAT/ ASCA is = 1.7 -2.0 steeper than the HardXRB (= 1.4). ASCA and SAX resolved ~ 30% of the hard XRB. The remaining ~ 70% is due to a population of absorbed sources seen with Chandra and XMM
Compton Thick sources QSOII 6 x 1023 cm-2 if Compton thin Norman et al. 2002 Evidence that the NIR light of QSOII is dominated by the host galaxy 20% of EROS among X-ray selected AGN ~ 20-40% of the QSOII pop (Brusa et al. 2004)
Very Hard LogN -LogS (5 -10 keV) CDFS 940 ks α = 1.35 XMM LH (Hasinger et al. 2001) Steep slope (~ Euclidean) Hardest sources missed by Chandra? The population of absorbed sources is still increasing at low fluxes How to detect these sources???
R-K vs NH BLAGN HEX LEX GAL
A mixed optical-X-ray classification BLAGN HEX LEX ABS 43% of X-ray detected AGN are classified as LEX+ABS Szokoly et al. 2004
CDFS Spectral ID Object class z<2 z>2 AGN -1 26-5 5-0 AGN -2 41-41 1-1 QSO -1 12-0 5-2 QSO -2 1-0 7-2 Galaxy 28-5 0 Clusters 5-1 0 Star 7 0 Total 138-57 Unsecure = 1 single line (OII, Ly) Szokoly et al. 2004
Soft X -ray Background Contribution from resolved sources below S= 10 -15 erg s-1 cm-2 in the 1 -2 keV band is 6.25 10 -13 erg cm-2 s-1 deg-2 (14% of the ROSAT value). A total of 83% of the ROSAT-XRB value is resolved. After adding a 6% from bright Clusters, we have a strict upper limit of 11% for the diffuse emission from warm gas (the hidden WHIM).
Early Type Galaxies Active SF Galaxies? First results from Deep Chandra Surveys: looking at galaxies at bright fluxes (2001) X-ray galaxies detected in the infrared, high FhardX/Fopt colors consistent with reddened elliptical at z ~ 1-2 possibly heavily obscured AGN and/or LMXB see also Crawford et al. 2001 Leitherer et al. 1995 Kennicutt 1992 SFR X= 2 -20 ×10 -40 L2-10 M⊙yr-1 For 9 emission line galaxies in the Lynx field (180 ks with Chandra) (Stern et al. 2001) SFR X= 10 3 ×SFROII Buried AGN rather than OB and HMXB in “normal” galaxies at high fluxes (XBONG).
Photometric redshifts: check on spectroscopic redshifts Hyperz: NUV U V B V R I Z J H K Zheng et al. 2004