On behalf of the XMM-Newton Survey Science Centre

On behalf of the

XMM-Newton Survey Science Centre

Roberto Della CecaINAF – Osservatorio Astronomico di

Brera,Milan

The Cosmological properties

of AGN in the XMM-Newton Hard Bright

Survey

http://www.inaf.it/index.html

Co-authors

A. Caccianiga (INAF –OABrera, Milan, Italy) P. Severgnini (INAF –OABrera, Milan, Italy)T. Maccacaro (INAF –OABrera, Milan, Italy)H. Brunner (Max Planck, Garching,

Germany) F.J. Carrera (IFCA, Santander, Spain)F. Cocchia (INAF-OARoma, Italy)S. Mateos (Leicester University, UK)M.J. Page (MSSL, UK)J.A. Tedds (Leicester University, UK)

Why hard X-ray surveys are important

Most direct probe of the SMBH accretion activity

SMBH census

Constraints to models for the formation and evolution of structures in the Universe

A few key questions….

Which are the cosmological properties (e.g. XLF) of the absorbed and unabsorbed AGN population?

Is the ratio absorbed/unabsorbed AGN a function of Lx and/or z?

How the results compare with the Unification models of AGN?

What about the heavily absorbed (NH>1024 cm-2) Compton Thick AGN?

The XMM Bright Survey is aimed at selecting and spectroscopically identifying a large and statistically representative sample of bright

(fx>~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 (HBSS)

The XMM-Newton Bright SurveyThe XMM-Newton Bright Survey

XMM fields used 237 Sources 400 (fx > ~7x10-14 cgs) Identified 348 (87%) (~240 sources from us)

Covered Area (deg2) 28 Spectroscopic Classification % Type 1 AGN 70% Type 2 AGN 10% Other Extragalactic 4% Stars 16%

The XMM-Newton Bright Survey in The XMM-Newton Bright Survey in pillspills

Optical and X-ray spectral analysis is possible for almost all the sources in the XBS!!

Della Ceca et al., 2004Caccianiga et al., 2008

The X-ray sky above 5 keV: the HBSS sampleThe X-ray sky above 5 keV: the HBSS sample

Intrinsic NH vs.

Intrinsic Lx

67 X-ray src65 with ID

Spectroscopic ID 97%

40 Unabsorbed AGN 22 Absorbed AGN

Int r

insic

NH

NH =4x1021

Intrinsic Luminosity

NH =4x1021 Av~2

Lx-z planeHBSS Sample

Unabsorbed AGN : 40 obj. Absorbed AGN : 22 obj.

<Log Lx> = 44.2<Log Lx> = 43.7

Redshift Distribution

Luminosity Distribution

Absorbed AGNvs.

Unabsorbed AGN

De-evolved (z=0) X-ray luminosity De-evolved (z=0) X-ray luminosity functionsfunctions

40 obj

22 obj

4x1021<NH<1024

NH<4x1021

Absorb

ed AGN h

ave a

ste

eper

XLF

than

the u

nabso

rbed o

nes1/Vmax method

(Schmidt, 1968),

correcting for the bias due

to the photoelectric absorption.

Fraction of absorbed AGN in the HBS Fraction of absorbed AGN in the HBS surveysurvey

Ab

sorb

ed

AG

N/A

ll A

GN

(N

H<

10

24 c

m-2)

HBSS

Beckman et al., 2006Bassani et al., 2006Markwardt et al., 2006Sazonov et al., 2007

Fraction = 0.570.11

Abs.AGN (4x1021<NH<1024 cm-2)----------------------------All AGN (NH<1024 cm-2)

Lx>3x1042 erg s-1

Fraction of absorbed AGN in the HBS Fraction of absorbed AGN in the HBS surveysurvey

Ab

sorb

ed

AG

N/A

ll A

GN

(N

H<

10

24 c

m-2)

HBSS

Beckman et al., 2006Bassani et al., 2006Markwardt et al., 2006Sazonov et al., 2007

From Integral/Swift• E> 10 keV

• fx>10-11 cgs

Lx>3x1042 erg s-1

Abs.AGN (4x1021<NH<1024 cm-2)----------------------------All AGN (NH<1024 cm-2)

Very

good a

greem

ent

Fraction of absorbed AGN vs. Intrinsic LxFraction of absorbed AGN vs. Intrinsic Lx

From the HBSS sample (z=0)using the best fit XLF

In agreement with e.g.: Ueda et al., 2003 La Franca et al., 2005Akylas et al., 2006Ballantyne et al., 2006

The frac

tion o

f obsc

ured A

GN

decreas

e with

L x

First pointed out by Lawrence and Elvis,1982

From the HBSS sample (z=0)

From Akylas et al., 2006

Fraction of absorbed AGN vs. Intrinsic LxFraction of absorbed AGN vs. Intrinsic Lx

<z>~0.8

<z>~1.2<z>~1.3

<z>~1.5

<z>~2.4

Redshift dependence?

From the HBSS sample (z=0)

Rescaled to z=0 using:~(1+z)0.4 from (Treister and Urry, 2006, Ballantyne et al., 2006)

Fraction of obscured AGN vs. Intrinsic LxFraction of obscured AGN vs. Intrinsic Lx

The frac

tion o

f obsc

ured A

GN

probab

ly in

creas

e with

z

See also La Franca et al., 2005

Comparison with Unification Comparison with Unification modelsmodels

The sim

plest

unifi

catio

n

schem

e of A

GN is ru

led o

ut

HBSS


Standard receding torus modelLawrence (1991)

h

rtorustorus

AGN

h

r

torustorus

AGN


Modified receding torus modelh L with =0.23

Simpson (2005); Honig and Beckert (2007)

Comparison with optical Comparison with optical samplessamples

HBSS

Fraction of optically Narrow line AGN Simpson (2005)

Compton ThinAND

Compton Thick

Only Compton Thin AGN

24214 EEThick NCN

)1(

)(

optx

xopt

FF

FFC

The intrinsic XLF of Compton Thick The intrinsic XLF of Compton Thick AGNAGN


XLFThick = 2 x XLF4E21-E24


XLFThick = 4 x XLF4E21-E24

XLFThick = XLF4E21-E24


Thick AGN from Sazonov et al., (2007)INTEGRAL 17-60 keV Sample

ID rate = 93%; 4 CT AGN

Independent measurements


Thick AGN from Daddi et al. (2007)

rescaled to z=0(Spitzer+Chandra) data



Thick AGN from Fiore et al. (2008)rescaled to z=0

(Spitzer+Chandra) dataONE OF THE NEXT TALKS



Very g

ood agre

ement w

ith

independent X

-ray-

infr

ared

sam

ples

of CT A

GN

Compton Thin AGN vs. Compton Thick Compton Thin AGN vs. Compton Thick AGNAGN

Compton Thick AGN NH>1024 cm-

2

----------------------------------------

Compton Thick AGN NH<1024 cm-

2

1.080.44

0.570.22

0.230.15The fr

actio

n of C

T AGN

decreas

e with

L x

ConclusionsWe have discussed here the HBSS AGN

sample. Absorbed AGN have a steeper XLF than the unabsorbed ones;

The intrinsic fraction of absorbed (Thin) AGN with Lx>~3x1042 cgs is 0.570.11. In excellent agreement with local samples of hard (>10 keV) selected AGN at a flux limit of 10-11 cgs; The fraction of abs. AGN is a function of Lx and, probably, of z;

Our results support the modified receding torus model;

We have derived, in an indirect way, the XLF of Compton Thick AGN and found that XLFThick ~ 2 x XLF4E21-E24;

The fraction Thick AGN/Thin AGN decreases with Lx.

The projects presented here have received partial financial support

from ASI, MIUR and INAF grants over the last few years.

THANKS

Astro-ph/0805.1919

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On behalf of the XMM-Newton Survey Science Centre