Statistical analysis of the X-ray Statistical analysis of the X-ray emission properties of type-1 emission properties of type-1

AGN in the AGN in the XMM-2dF Wide Angle SurveyXMM-2dF Wide Angle Survey

Silvia MateosLeicester University (UK)

M.G. Watson, J. A. Tedds and Y. Xu Leicester University (UK)Leicester University (UK)M. Page Mullard Space Science Laboratory-UCL (UK)Mullard Space Science Laboratory-UCL (UK)F.J. Carrera and A. Corral Instituto de Física de Cantabria CSIC-UC (SpainInstituto de Física de Cantabria CSIC-UC (Spain)A. Schwope and M. Krumpe Astrophysikalisches Institut Potsdam (Germany)Astrophysikalisches Institut Potsdam (Germany)

MotivationMotivation

The sample of type-1 AGN in XMM-2dF Wide Angle Survey is one of the largest samples of X-ray selected type-1 AGN assembled so far

Unique resource to characterise the X-ray emission properties of the dominant population of sources at fluxes ~10-14 erg cm-2 s-1, where the bulk of the Cosmic X-ray Background (CXRB) emission originates:

•Broad band continuum shape and intrinsic dispersion

•Fraction of X-ray absorbed type-1 AGN and distribution of absorbing column densities •Dependence of emission properties on the X-ray luminosity of the objects and redshift

XMM-2dF Wide Angle SurveyXMM-2dF Wide Angle Survey

2dF optical multi-fibre spectroscopy on the AAT obtained for 68 XMM-Newton fields (texp ~ few tens of ksec) over a total area >15 deg2

More than 3000 sources with X-ray fluxes above ~10-14 cgs and optical counterparts brighter than V~21 observed and reduced

978 serendipitous X-ray sources with 0.5-4.5 keV flux >10-14 erg cm-2 s-1 spectroscopically identified

Type Number

BLAGN 641 (65.5%)

NELG 157 (16%)

Gal 57 (5.8%)

Stars 123 (12.6%)

Type-1 AGN in the XMM-2dF Wide Angle SurveyType-1 AGN in the XMM-2dF Wide Angle Survey

Typical fluxes ~break in the X-ray Typical fluxes ~break in the X-ray source countssource counts

2-10 keV flux2-10 keV flux

496496 type-1 AGN with type-1 AGN with ≥≥75 EPIC counts 75 EPIC counts selected for X-ray spectral analysisselected for X-ray spectral analysis

X-ray spectral analysisX-ray spectral analysis

Power law and absorbed power law (both absorbed by the Galaxy) models fitted to all 0.2-12 keV X-ray spectra

Single-source analysis of brightest objects (down to 200 EPIC counts, 300 objects) now completed

F-test significance ≥95% to accept additional spectral components

Overal results of spectral fits:Overal results of spectral fits:

381 (~77%)381 (~77%) best fitted with a power law best fitted with a power law

37 (~7.5%)37 (~7.5%) objects with detected absorption objects with detected absorption

78 (~15.7%)78 (~15.7%) objects with detected soft excess objects with detected soft excess emissionemission

=1.95 ± 0.04=0.20 ± 0.03

Broad band continuum shape(I)Broad band continuum shape(I)

The 0.2-12 keV X-ray spectra type-1 AGN best fitted with a power law of ~1.9. However significant intrinsic dispersion

in measured values detected

Broad band continuum shape(II)Broad band continuum shape(II)

No clear cosmic evolution of the mean continuum No clear cosmic evolution of the mean continuum shape of type-1 AGN up to z~3shape of type-1 AGN up to z~3

Broad band continuum shape(III)Broad band continuum shape(III)

The 0.2-12 keV continuum shape does not show The 0.2-12 keV continuum shape does not show obvious dependence with X-ray luminosity obvious dependence with X-ray luminosity

from 10from 104343-10-104545 erg s erg s-1-1

2-10 keV lum2-10 keV lum

Excess absorption in type-1 AGN(I)Excess absorption in type-1 AGN(I)

No correlation between No correlation between and N and NHH

Typical values of absorbing Typical values of absorbing column density Ncolumn density NHH~ few 10~ few 102121cmcm-2-2

For sources with NFor sources with NHH>10>102222 cm cm-2-2 existing existing

correlation of optical and correlation of optical and X-ray emission properties unclearX-ray emission properties unclear

X-ray absorption detected (F-testX-ray absorption detected (F-test≥95%≥95%) in 37 type-1 AGN (~7%)) in 37 type-1 AGN (~7%)

Excess absorption in type-1 AGN(II)Excess absorption in type-1 AGN(II)

Detection of X-ray absorption in type-1AGN does not occur at Detection of X-ray absorption in type-1AGN does not occur at any preferred X-ray luminosity or redshiftany preferred X-ray luminosity or redshift

<L<L2-102-10> = 44.17 unabsorbed type-1 AGN> = 44.17 unabsorbed type-1 AGN

<L<L2-102-10> = 44.25 absorbed type-1 AGN> = 44.25 absorbed type-1 AGN

No evident dependence of X-ray absorbing column No evident dependence of X-ray absorbing column densities detected in type-1 AGN with luminosity or redshift densities detected in type-1 AGN with luminosity or redshift

Excess absorption in type-1 AGN(III)Excess absorption in type-1 AGN(III)

ConclusionsConclusions

0.2-12 keV emission0.2-12 keV emission of most type-1 AGN best fitted with a of most type-1 AGN best fitted with a powerpower law law • mean continuum shape ~1.95 mean continuum shape ~1.95 • intrinsic dispersion ~0.20 intrinsic dispersion ~0.20

Continuum shape Continuum shape • no significant evolution up to redshifts of ~3no significant evolution up to redshifts of ~3• no luminosity dependence in range 10no luminosity dependence in range 104343-10-104545erg serg s-1-1

X-ray absorption detected in ~7% of our type-1 AGNX-ray absorption detected in ~7% of our type-1 AGN •absorbedabsorbed type-1 AGN do not seem to occur preferentially at type-1 AGN do not seem to occur preferentially at any particular redshift or luminosityany particular redshift or luminosity• no obvious dependence of Nno obvious dependence of NHH with redshift or luminosity with redshift or luminosity• typical values ~10typical values ~102121 cm cm-2 -2 –a substantial fraction with detected –a substantial fraction with detected NNHH>10>1022 22 cmcm-2-2

• Existing correlation of optical and X-ray properties unclearExisting correlation of optical and X-ray properties unclear

Broad band continuum shape(IV)Broad band continuum shape(IV)

The hardening of The hardening of with X-ray flux known to be mostly due to with X-ray flux known to be mostly due to undetected X-ray absorptionundetected X-ray absorption

2-10 keV flux2-10 keV flux0.5-2 keV flux0.5-2 keV flux