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Absorbed and unabsorbed AGN in the XMM-Newton
Hard Bright Survey
R. Della Ceca A. Caccianiga P. Severgnini T.
Maccacaro INAF Osservatorio Astronomico di
Brera,Milan F. Cocchia (INAF-OARome, Italy) V.
Braito (Hopkins Univ. and GSFC, USA)
On behalf of the XMM-Newton Survey Science
Centre
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The XMM-Newton Bright Survey Project

• The XMM Bright Survey is aimed at selecting and
  spectroscopically identifying a large and
  statistically representative sample of bright (fx
  gt 7x10-14 c.g.s) serendipitous XMM sources in
  two complementary energy bands

0.5-4.5 keV energy band Bright Sample (BS)
4.5-7.5 keV energy band Hard Bright Sample (HBS)
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• The XMM BSS in the survey context

XMM-Newton Bright Survey
BS ? 389 sources HBS ? 67 sources (56 sources
in common)
Adapted from Alexander et al.,2003
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• The XMM BSS and the optical ID

Chandra , XMM Deep Medium
ASCA BeppoSAX
HEAO 1
Photometric z X etc..
10 meters class telescope
XMM BSS
4 meters class telescope
Broad Line AGNs
Optical and X-ray spectral analysis is possible
for almost all the sources in the XMM BSS!!
Adapted from Akiyama et al., 2003
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Optical identification classification
(240 sources our own spectroscopy)
BS HBS Sources
389 67 Identified
337 (87) 65 (97) Class
Type 1 AGN
72 65 (Sey1Sey1.5QSO
NLSy1) Type 2 AGN 6
31 (Sey2Sey1.8Sey1.9QSO2)
Other Extragalactic 5
1 (Normal Gal., Clust.,BL Lacs) Stars
17 3 (Normal stars,
Binary System)
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7 Type 2 QSO
HBS sample
Intrinsic NH vs. Intrinsic Lx
Good agreement with AGN Unification Scheme
Type 2 QSO X-ray Def. Lxgt1044 cgs NHgt1022
cm-2
Opt. Type 1 AGN Opt. Type 2 AGN Opt. Diluted AGN
See Caccianiga et al., 20042007
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Observed NH Distribution
Upper limits
NH 4x1021
Detection
40 Unabsorbed AGN 22 Absorbed AGN
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Lx-z plane
HBS Sample
Redshift Distribution
Unabsorbed AGN 40 obj. Absorbed AGN 22
obj.
Luminosity Distribution
ltLog Lxgt 44.2
ltLog Lxgt 43.7
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HBS AGN Sample Cosmological Evolution
LDDE Model (from Ueda et al., 2003)
V/Vmax method P16.5?3
Unconstrained from the present sample. Fixed
from La Franca et al., 2005
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Comparison with other samples
HBS AGN Sample ? P16.5?3
(2-10 keV) X-ray selected Samples
Ueda et al., 2003 ? P14.2?0.4 La
Franca et al., 2005 ? P14.6?0.3 Optically
selected type-1 AGN VVDS sample Bongiorno et
al., 2007 ? P16.5 Multi-wavelength samples of
AGN (from IR to hard X) Hopkins et al., 2007
? P15.95?0.23
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De-evolved (z0) X-ray luminosity function
1/Vmax method (Schmidt, 1968)
Local (zlt0.1) XLF from Shinozaki et al.,
2006 HEAO1 samples
Absorbed plus unabsorbed AGN
De-evolved XLF obtained using the best fit LDDE
model
Local (zlt0.1) XLF from Sazonov et al.,
2004 RXTE All-sky survey
XLF (z0) from the HBS sample
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De-evolved (z0) X-ray luminosity functions
Absorbed AGN vs. unabsorbed AGN
40 obj
22 obj
Absorbed AGN have a steeper XLF than the
unabsorbed ones
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Fraction of absorbed AGN in the HBS survey
Abs.AGN (NHgt4x1021 cm-2) ---------------------- Al
l AGN (NHlt1024 cm-2)
Beckman et al., 2006
Bassani et al., 2006
Markwardt et al., 2006
HBS
Sazonov et al., 2007
Absorbed AGN/All AGN (NHlt1024 cm-2)
Fraction 0.57?0.11
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Fraction of obscured AGN in the HBS survey
Abs.AGN (NHgt4x1021 cm-2) ---------------------- Al
l AGN (NHlt1024 cm-2)
Beckman et al., 2006
Bassani et al., 2006
Markwardt et al., 2006
HBS
Sazonov et al., 2007
Absorbed AGN/All AGN (NHlt1024 cm-2)

• From Integral/Swift
• Egt 10 keV
• fxgt10-11 cgs

Very good agreement
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Fraction of obscured AGN vs. Intrinsic Lx
First pointed out by Lawrence and Elvis,
1982 Recently Ueda et al., 2003 La Franca et
al., 2005 Akylas et al., 2006
From the HBS sample (z0) using the best fit XLF
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Fraction of obscured AGN vs. Intrinsic Lx
From Akylas et al., 2006
ltzgt0.8
ltzgt2.4
ltzgt1.2
ltzgt1.3
ltzgt1.5
From the HBS sample (z0)
Redshift dependence?
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Fraction of obscured AGN vs. Intrinsic Lx
Rescaled to z0 using ltzgt (1z)0.5 from
Treister and Urry, 2006
From the HBS sample (z0)
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NH distribution between 1021 and 1024
INTEGRAL/SWIFT Beckman et al., 2006 Bassani et
al., 2006 Markwardt et al., 2006
Risaliti et al 1999 Optically selected sample of
Sy2
HBS
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Conclusions
We have discussed here the HBS AGN sample.

• The AGN XLF (z0) is in good agreement with the
  local RXTE AGN XLF. A smaller amplitude is
  observed is compared with the local HEAO1 AGN XLF

• Absorbed AGN have a steeper XLF than the
  unabsorbed ones

• The intrinsic fraction of absorbed AGN with Lx gt
  3x1042 cgs is 0.57?0.11. In excellent agreement
  with local samples of hard (gt10 keV) selected
  AGN at a flux limit of 10-11 cgs

• The fraction of absorbed AGN is a function of Lx
  and, probably, of the redshift

• We find a flat Log NH distribution for NH
  between 1021 and 1024.
• In very good agreement with local samples of hard
  (gt10 keV)
• selected AGN at a flux limit of 10-11 cgs

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THANKS

• This project has received partial financial
  support from ASI and/or MURST (COFIN) grants over
  the last few years.
• We also thank the TNG, ESO and Calar Alto Time
  Allocation Committee for a generous and
  continuous allocation of observing time.