Average Fe Kα emission from distant AGN Amalia Corral IFCA(Santander)/OAB(Milano) M.J. Page: MSSL (UCL), UK F.J. Carrera, X. Barcons, J. Ebrero: IFCA (CSIC-UC), Spain S. Mateos, J.A. Tedds, M.G. Watson: University of Leicester, UK A. Schwope, M. Krumpe: Astrophysikalisches Institut Postdam, Germany X-ray Universe 2008, Granada, 27th May 2008

Introduction Inclination angle Maximum-rotating BH Non-rotating BH XRB (X-Ray Background) is known to be composed of discrete sources, most of them are AGN. XRB synthesis models, ingredients: - AGN intrinsic column density and acretion rate distribution and their evolution as a function of Luminosity and redshift. - Average radiative efficiency of accretion onto Supermassive Black Holes -> Measure from Fe line relativistic profile.

Previous Results Local samples: EW(relativistic) ~ 100-200 eV (Guainazzi+06, Nandra+07) Distant AGN -> average or stack many spectra together: EW(relativistic) ~ 400 (type1) - 600(type2) eV (Streblyanska+05,Brusa+05)

Our sample AGN from the AXIS (An International XMM-Newton Survey) and XWAS (XMM-Newton Wide Angle Survey) medium surveys (average flux ~ 5x10-14 erg cm-2 s-1) . Optical spectroscopic identifications (>80 counts 0.2-12 keV): Type 1 AGN: 606 sources Type 2 AGN: 117 sources

Our sample Sample selection: Individual spectra > 80 counts in 0.2-12 keV

Averaging method Fit an absorbed power law above 1 keV rest-frame and unfold the un-grouped spectra: best-fit model. Correct for Galactic Absorption. Shift to rest-frame. Normalize using the 2-5 keV rest-frame band. Rebin to 1000 final counts/bin. Average.

Fit simple power law in 2-10 keV : Results Type 1 AGN > 200000 counts Type 2 AGN ~ 30000 counts Fit simple power law in 2-10 keV : Type 1: Γ=1.92±0.02 Type 2: Γ=1.44±0.02

Broad relativistic profile not clearly present Results Type 1 AGN > 200000 counts Type 2 AGN ~ 30000 counts Broad relativistic profile not clearly present

Simulations 100 simulations (best-fit model) per real spectrum including Poisson counting noise and keeping the same 2-8 keV observed flux, exposure time and calibration matrices as for the real data. Significance contours by removing the 32% (1σ level) and 5% (2σ level) extreme values.

Results ● Simulated continuum ▪ Average spectrum ·· 1σ confidence limit -- 2σ confidence limit ▪ Average spectrum ● Simulated continuum

Results ● Simulated continuum ▪ Average spectrum ·· 1σ confidence limit -- 2σ confidence limit ▪ Average spectrum ● Simulated continuum

Spectral fit Baseline model: 100-simulations continuum: mixture of absorbed power laws. Narrow emission line.

Spectral fit – Type 1 AGN Best-fit model: Baseline model plus neutral reflection: Egaus = 6.36±0.05 keV σgaus = 80±80 eV EWgaus = 90±30 eV i = 60±20º R=0.5±0.20

Spectral fit – Type 1 AGN Best-fit model: Baseline model plus neutral reflection: Egaus = 6.36±0.05 keV σgaus = 80±80 eV EWgaus = 90±30 eV i = 60±20º R=0.5±0.20

EW(broad relativistic line) < 400 eV at 3σ confidence level Spectral fit – Type 1 AGN Best-fit model: Baseline model plus neutral reflection: Egaus = 6.36±0.05 keV σgaus = 80±80 eV EWgaus = 90±30 eV i = 60±20º R=0.5±0.20 EW(broad relativistic line) < 400 eV at 3σ confidence level

Spectral fit – Type 2 AGN Model: Baseline model plus neutral reflection: Egaus = 6.36±0.07 keV σgaus = 80±60 eV EWgaus = 70±30 eV i < 80 R > 0.7

Spectral fit – Type 2 AGN Model: Baseline model plus neutral reflection: Egaus = 6.36±0.07 keV σgaus = 80±60 eV EWgaus = 70±30 eV i < 80 R > 0.7

Spectral fit – Type 2 AGN Model: Baseline model plus Laor line: Egaus = 6.36±0.07 keV Elaor ~ 6.7 keV σgaus = 80±60 eV EWgaus = 70±40 eV EWlaor ~ 300 eV i ~ 60º

Spectral fit – Type 2 AGN Model: Baseline model plus Laor line: Egaus = 6.36±0.07 keV Elaor ~ 6.7 keV σgaus = 80±60 eV EWgaus = 70±40 eV EWlaor ~ 300 eV i ~ 60º

Neutral reflection and Relativistic line give the same fit Spectral fit – Type 2 AGN Model: Baseline model plus Laor line: Egaus = 6.36±0.07 keV Elaor ~ 6.7 keV σgaus = 80±60 eV EWgaus = 70±40 eV EWlaor ~ 300 eV i ~ 60º Neutral reflection and Relativistic line give the same fit

Type 1 AGN: sub-samples Number of counts 2-10 keV > 2x105 allow us to test evolution with different parameters by dividing the sample in 3 subsamples of equal quality (i.e. number of total counts): redshift, flux and luminosity. We found no dependence for the emission features on redshift or flux. Dependence on Luminosity -> Iwasawa- Taniguchi effect?

Type 1 AGN: sub-samples L(0.5-2 keV) (erg s-1) EW narrow line (eV) 1x1042 – 2x1044 190±50 2x1044 – 6x1044 150±80 6x1044 – 6x1046 50±40

Conclusions Narrow emission line significatively detected in Type 1 and Type 2 AGN average spectra. E ~ 6.4 keV, EW ~ 100 eV. Type 1 AGN: No compelling evidence of a Broad component in the average spectrum. Continuum features best represented by a reflection component. Relativistic line upper limit EW<400 eV (3σ confidence). Iwasawa-Taniguchi effect for narrow line component marginally detected. Type 2 AGN: Statistics insufficient to distinguish between a relativistic line and a reflection component.

Conclusions Narrow emission line significatively detected in Type 1 and Type 2 AGN average spectra. E ~ 6.4 keV, EW ~ 100 eV. Type 1 AGN: No compelling evidence of a Broad component in the average spectrum. Continuum features best represented by a reflection component. Relativistic line upper limit EW<400 eV (3σ confidence). Iwasawa-Taniguchi effect for narrow line component marginally detected. Type 2 AGN: Statistics insufficient to distinguish between a relativistic line and a reflection component.

Conclusions Narrow emission line significatively detected in Type 1 and Type 2 AGN average spectra. E ~ 6.4 keV, EW ~ 100 eV. Type 1 AGN: No compelling evidence of a broad component in the average spectrum. Continuum features best represented by a reflection component. Relativistic line upper limit EW<400 eV (3σ confidence). Iwasawa-Taniguchi effect for narrow line component marginally detected. Type 2 AGN: Statistics insufficient to distinguish between a relativistic line and a reflection component.

Conclusions Narrow emission line significatively detected in Type 1 and Type 2 AGN average spectra. E ~ 6.4 keV, EW ~ 90 eV. Type 1 AGN: No compelling evidence of a broad component in the average spectrum. Continuum features best represented by a reflection component. Relativistic line upper limit EW<400 eV (3σ confidence). Iwasawa-Taniguchi effect for narrow line component marginally detected. Type 2 AGN: Statistics insufficient to distinguish between a relativistic line and a reflection component.

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