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Silvia Mateos Leicester University (UK)

Statistical analysis of the X-ray emission properties of type-1 AGN in the XMM-2dF Wide Angle Survey. Silvia Mateos Leicester University (UK). M.G. Watson, J. A. Tedds and Y. Xu Leicester University (UK) M. Page Mullard Space Science Laboratory-UCL (UK)

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Silvia Mateos Leicester University (UK)

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  1. Statistical analysis of the X-ray emission properties of type-1 AGN in the XMM-2dF Wide Angle Survey Silvia Mateos Leicester University (UK) • M.G. Watson, J. A. Tedds and Y. Xu Leicester University (UK) • M. Page Mullard Space Science Laboratory-UCL (UK) • F.J. Carrera and A. Corral Instituto de Física de Cantabria CSIC-UC (Spain) • A. Schwope and M. Krumpe Astrophysikalisches Institut Potsdam (Germany)

  2. Motivation • 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

  3. XMM-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

  4. Type-1 AGN in the XMM-2dF Wide Angle Survey 496 type-1 AGN with ≥75 EPIC counts selected for X-ray spectral analysis 2-10 keV flux Typical fluxes ~break in the X-ray source counts

  5. X-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: 381 (~77%) best fitted with a power law 37 (~7.5%) objects with detected absorption 78 (~15.7%) objects with detected soft excess emission

  6. 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 =1.95 ± 0.04 =0.20 ± 0.03

  7. Broad band continuum shape(II) No clear cosmic evolution of the mean continuum shape of type-1 AGN up to z~3

  8. Broad band continuum shape(III) 2-10 keV lum The 0.2-12 keV continuum shape does not show obvious dependence with X-ray luminosity from 1043-1045 erg s-1

  9. Excess absorption in type-1 AGN(I) X-ray absorption detected (F-test≥95%) in 37 type-1 AGN (~7%) No correlation between  and NH Typical values of absorbing column density NH~ few 1021cm-2 For sources with NH>1022 cm-2 existing correlation of optical and X-ray emission properties unclear

  10. Excess absorption in type-1 AGN(II) Detection of X-ray absorption in type-1AGN does not occur at any preferred X-ray luminosity or redshift <L2-10> = 44.17 unabsorbed type-1 AGN <L2-10> = 44.25 absorbed type-1 AGN

  11. Excess absorption in type-1 AGN(III) No evident dependence of X-ray absorbing column densities detected in type-1 AGN with luminosity or redshift

  12. Conclusions • 0.2-12 keV emission of most type-1 AGN best fitted with a power law • mean continuum shape ~1.95 • intrinsic dispersion ~0.20 • Continuum shape • no significant evolution up to redshifts of ~3 • no luminosity dependence in range 1043-1045erg s-1 • X-ray absorption detected in ~7% of our type-1 AGN • absorbedtype-1 AGN do not seem to occur preferentially at • any particular redshift or luminosity • no obvious dependence of NH with redshift or luminosity • typical values ~1021 cm-2 –a substantial fraction with detected • NH>1022 cm-2 • Existing correlation of optical and X-ray properties unclear

  13. Broad band continuum shape(IV) 0.5-2 keV flux 2-10 keV flux The hardening of  with X-ray flux known to be mostly due to undetected X-ray absorption

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