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See detail3{sigma} hard sample of XMDS survey (Tajer+, 2007)
Tajer, M.; Polletta, M.; Chiappetti, L. et al

Textual, factual or bibliographical database (2007)

Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected ... [more ▼]

Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample with wide multiwavelength coverage. We selected a sample of 136 X-ray sources detected at a significance of >=3{sigma} in the 2-10keV band (F[SUB]2-10[/SUB]>~10[SUP]-14[/SUP]erg/cm[SUP]2[/SUP]/s) in a ~1deg[SUP]2[/SUP] area in the XMM Medium Deep Survey (XMDS, Cat. ). The XMDS area is covered with optical photometry from the VVDS and CFHTLS surveys and infrared Spitzer data from the SWIRE survey. Based on the X-ray luminosity and X-ray to optical ratio, 132 sources are likely AGN, of which 122 have unambiguous optical - IR identification. The observed optical and IR spectral energy distributions of all identified sources are fitted with AGN/galaxy templates in order to classify them and compute photometric redshifts. X-ray spectral analysis is performed individually for sources with a sufficient number of counts and using a stacking technique for subsamples of sources at different flux levels. Hardness ratios are used to estimate X-ray absorption in individual weak sources. (1 data file). [less ▲]

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See detailSpectral Energy Distributions of Hard X-Ray Selected Active Galactic Nuclei in the XMM-Newton Medium Deep Survey
Polletta, M.; Tajer, M.; Maraschi, L. et al

in Astrophysical Journal (2007), 663

We present the SEDs of a hard X-ray selected sample containing 136 sources with F[SUB]2-10keV[/SUB]>10[SUP]-14[/SUP] erg cm[SUP]-2[/SUP] s[SUP]-1[/SUP] 132 are AGNs. The sources are detected in a 1 deg ... [more ▼]

We present the SEDs of a hard X-ray selected sample containing 136 sources with F[SUB]2-10keV[/SUB]>10[SUP]-14[/SUP] erg cm[SUP]-2[/SUP] s[SUP]-1[/SUP] 132 are AGNs. The sources are detected in a 1 deg[SUP]2[/SUP] area of the XMM-Newton Medium Deep Survey where optical data from the VVDS and CFHTLS and infrared data from the SWIRE survey are available. Based on a SED fitting technique we derive photometric redshifts with sigma(1+z)=0.11 and 6% of outliers and identify AGN signatures in 83% of the objects. This fraction is higher than derived when a spectroscopic classification is available. The remaining 17[SUP]+9[/SUP][SUB]-6[/SUB]% of AGNs show star-forming galaxy SEDs (SF class). The sources with AGN signatures are divided in two classes, AGN1 (33[SUP]+6[/SUP][SUB]-1[/SUB]%) and AGN2 (50[SUP]+6[/SUP][SUB]-11[/SUB]%). The AGN1 and AGN2 classes include sources whose SEDs are fitted by type 1 and type 2 AGN templates, respectively. On average, AGN1s show soft X-ray spectra, consistent with being unabsorbed, while AGN2s and SFs show hard X-ray spectra, consistent with being absorbed. The analysis of the average SEDs as a function of X-ray luminosity shows a reddening of the infrared SEDs, consistent with a decreasing contribution from the host galaxy at higher luminosities. The AGNs in the SF classes are likely obscured in the mid-infrared, as suggested by their low L[SUB]3-20mum[/SUB]/L[SUP]corr[/SUP][SUB]0.5-10keV[/SUB] ratios. We confirm the previously found correlation for AGNs between the radio luminosity and the X-ray and the mid-infrared luminosities. The X-ray-radio correlation can be used to identify heavily absorbed AGNs. However, the estimated radio fluxes for the missing AGN population responsible for the bulk of the background at E>10 keV are too faint to be detected even in the deepest current radio surveys. [less ▲]

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