Transcript Slide 1

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 SAX Vecchi et al. 1999
ASCA2 Ishisaki et al. 1999
ASCA1 Ueda 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
Compton thick candidates
NH vs redshifts for the whole sample
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. 2004
Tozzi et al. 2005
NH distribution vs Optical Type
Whole sample (321)
QSOII (44)
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
Whole sample (321)
Cthick candidates (14)
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 antihierarchical 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)
Compute the contribution of the absorbed sources to the XRB
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
Norman et al. 2004
Lilly et al. 1996
Lines from 60 m
Saunders et al. 1990, Takeuchi et al. 2003
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
Gilli et al. 2004
Prospects for the current X-ray surveys
Extended CDFS
Lehmer et al. 2005
0.3 deg2, 4 pointings, 250 ksec each
COSMOS XMM
Hasinger et al. 2006
2 deg2, 25 pointings, 60 ksec each
Other wide X-ray surveys: Bootes (9 deg2); ELAIS (1 deg2)
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 Xray 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 componen
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
XRBmost
is the
of the
ROSAT and ASCA
resolved
of theecho
Soft XRB.
Theformation
spectral index of
of AGNs
detected with ROSAT/ ASCA is = 1.7 -2.0 steeper than the Hard XRB (= 1.4).
ASCA and SAX resolved ~ 30% of the hard XRB. The remaining ~ 70% is due to
through
of the
population of absorbed
sourcesthe
seenhistory
with Chandra
and Universe
XMM
Massive Black Holes
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
XMM LH
α = 1.35
(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
AGN -2
QSO -1
QSO -2
Galaxy
Clusters
Star
26-5
41-41
12-0
1-0
28-5
5-1
7
5-0
1-1
5-2
7-2
0
0
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).
First results from Deep Chandra Surveys:
looking at galaxies at bright fluxes (2001)
Early Type Galaxies
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
Active SF Galaxies?
SFR X= 2 -20 ×10
-40 L
2-10
SFR X= 10 3 ×SFROII
M⊙yr-1
Leitherer et al. 1995
Kennicutt 1992
For 9 emission line galaxies
in the Lynx field (180 ks with
Chandra) (Stern et al. 2001)
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
Comparing CDFS and
K20 surveys (Cimatti et al.
2002): clear large scale
structures are detected
as two narrow (dz<0.02)
spikes at
z = 0.67 (19 obj)
z = 0.73 (19 obj)
+
z=1.04 (6 obj)
z=1.22 (4 obj)
z=1.62 (5 obj)
z= 2.57 (4 obj)
Gilli et al. 2003
Gilli 2003
Tracing the accretion power is not straightforward even in X-ray
(see Brandt et al. 2004)
25 ksec
October 15, 1999
0.5 -7 keV
OCTOBER
1999
118 ksec
174 ksec
303 ksec
333 ksec
392 ksec
515 ksec
645 ksec
740 ksec
808 ksec
939 ksec
Fsoft= 5.5 × 10 -17 erg s -1 cm -2
Fhard= 4.5 × 10 -16 erg s -1 cm -2
DECEMBER
2000
HEX
?
BLAGN
?
BLAGN
Szokoly et al. 2004
BLAGN
?
LEX
Szokoly et al. 2004
BPZ
F435w F606w F775w F850lp J H K (ISAAC)
Zheng et al. 2004
Mainieri et al. 2004
Net detected counts in the 0.5-2 keV and 2-7 keV bands
for the 366 sources in the CDFS
CDFS+CDFN XLF
CDFS spectroscopic galaxy sample with the 60 m warm LF, and spectral energy
distribution used for k-correction (hot gas from superwinds and X-ray binaries emission).
Better agreement with IR sample (maybe hint of some AGN contamination).
Norman et al. 2004
IR Bright Galaxies at z~2 with massive SFR
Nine K-band luminous galaxies at 1.7 < z < 2.3, with SFR ~ 100-500 M⊙ /yr
(LX<1042 erg/s, stacked X-ray img gives 100 M⊙ /yr each, except one with
L2-10 ~3× 1042 erg/s, SFR~ 500M⊙/yr. Stellar masses M > 1011 M⊙ for most of
They contribute a SFR Density of 0.04 M⊙ /yr/Mpc
Therefore we are witnessing the massive spheroid formation epoch
(the peak of just the low-z tail?)
They already outnumber by more than 1 order of mag the predictions of
hierarchical models of galaxy formation (despite the spectral incompletenes
ACS-F435W
ACS-F850LP
VLT-ISAAC
Daddi et al. 2004
X-ray properties of Radio sources
Science:
Search for Radio emission from heavily obscured AGN (among the X-ray
detected, not the missed ones as in Donley et al.)- Radio compactness vs NH
Decoupling SF Galaxies from AGN?
Distribution of AGN vs SF activity as a function of Radio flux for X-ray
detected sources.
X-ray non detected: SF high-z galaxies or strongly absorbed AGN?
Average X-ray spectral properties of non-detections.
....
To Do:
Photometry of Radio-only sources in the new ECDFS sources
Separate pointlike sources from jets.
Stacked spectra of X-ray non detections (1Ms and ECDFS)
....
Distribution of optical
type among the 27
sources with
good optical
spectroscopy
(fluxes and luminosities)
Obscured fraction vs redshift
Tozzi et al. 2005
Ueda et al. 2003