Spectral Energy Distributions of Hard X-ray selected AGNs in the XMDS Survey

By M. Polletta, M. Tajer, L. Maraschi, G. Trinchieri, C. Lonsdale, L. Chiappetti, S. Andreon, M. Pierre, O. Fèvre, G. Zamorani and 11 more. 2007

414 citations recorded by the source corpus.

We present the spectral energy distributions (SEDs) of a hard X-ray selected sample. The sample contains 136 sources with F(2-10 keV)>10^-14 erg/cm^2/s and 132 are AGNs. The sources are detected in a 1 square degree area of the XMM-Newton-Medium Deep Survey where optical data from the VVDS, CFHTLS surveys, 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+9-6% of AGNs shows star-forming galaxy SEDs (SF class). The sources with AGN signatures are divided in two classes, AGN1 (33+6-1%) and AGN2 (50+6-11). 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 IR 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(3-20micron)/Lcorr(0.5-10 keV) 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.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/18895e358647103a58abf39f3cc996742be28f29

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

THE NEXT GENERATION ATLAS OF QUASAR SPECTRAL ENERGY DISTRIBUTIONS FROM RADIO TO X-RAYS (2011, background): “Other investigations of SEDs have focused on subclasses, like broad absorption line (BAL) quasars (e.g., Gallagher et al. 2007), 2MASS red quasars (Kuraszkiewicz et al. 2009), hard X-ray selected quasars (Polletta et al. 2000, 2007), or on individual objects (e.g., Zheng et al. 2001).”
PHOTOMETRIC REDSHIFT AND CLASSIFICATION FOR THE XMM–COSMOS SOURCES (2008, methodology): “While it is known that low luminosity AGN may have MB fainter than our limit, to use a lower threshold of MB=-19 (as used by Polletta et al. 2007 and Rowan-Robinson et al. 2008), would increase the degeneracy between galaxy and AGN templates and thus the outliers from 6.3% to 8.0%.”
CHASING HIGHLY OBSCURED QSOs IN THE COSMOS FIELD (2008, methodology): “To characterize the infrared SED of the MIPS selected sources we fitted the SED with a library of empirical templates (Polletta et al. 2007, Pozzi et al. 2007, F08, Salvato et al. 2008), fixing the redshift to the spectroscopic redshift or, if this is not available, to the photometric redshift.”
The WIRCam Deep Survey I. Counts, colours, and mass-functions derived from near-infrared imaging in the CFHTLS deep fields (2011, methodology): “As in Ilbert et al. (2009), we use a combination of the Polletta et al. (2007) templates with the additional templates generated by Ilbert et al. (2009) to account for starbursts with ages of 0.3 to 3 Gyr.”
Star formation and mass assembly in high-redshift galaxies (2009, methodology): “Polletta et al. (2007) templates is reported in Fig.”
COLOR–MAGNITUDE RELATIONS OF ACTIVE AND NON-ACTIVE GALAXIES IN THE CHANDRA DEEP FIELDS: HIGH-REDSHIFT CONSTRAINTS AND STELLAR-MASS SELECTION EFFECTS (2010, methodology): “We also used the 10 AGN templates of Polletta et al. (2007) that include a variety of empirical quasar and Seyfert templates.”
Euclid preparation (2021, methodology): “We adopted a set of 33 templates from Polletta et al. (2007), which was complemented with templates from Bruzual & Charlot (2003).”
The mean star formation rate of X-ray selected active galaxies and its evolution from z~2.5: results from PEP-Herschel (2012, methodology): “For the SF templates, we consider the five basis SEDs from Mullaney et al. (2011) and add an M82like and Arp220-like SED from the SWIRE template library 2 available from http://sites.google.com/site/decompir/ (Polletta et al. 2007) to incorporate strongly star-bursting and ULIRG-like systems.”
Fitting the integrated spectral energy distributions of galaxies (2010, methodology): “Polletta et al. (2007) published a set templates that combine the SEDs of galaxies with those of AGN and thus fill an important hole in many SED fitting template sets.2 The library contains 20 templates including 1 elliptical, 7 spirals, 3 starbursts, 6 AGNs, and 3 composite (starburst + AGN)…”
THE LESSER ROLE OF STARBURSTS IN STAR FORMATION AT z = 2 (2011, methodology): “IR luminosities (hence SFRs) are derived from PACS fluxes using a set of empirical templates of local objects (Polletta et al. 2007; Gruppioni et al. 2010) as described in Rodighiero et al. (2010a).”
Characterization of Scuba-2 450 μm and 850 μm selected galaxies in the COSMOS field (2013, methodology): “Stellar population templates (Polletta et al. 2007; Bruzual & Charlot 2003) were assumed as input to Le Phare.”
CLASH: THREE STRONGLY LENSED IMAGES OF A CANDIDATE z ≈ 11 GALAXY (2012, methodology): “This includes three ellipticals and seven spirals as generated by Polletta et al. (2007) using the GRASIL code (Silva et al. 1998), as well as 12 starburst galaxies with ages ranging from 30 Myr to 3 Gyr generated by GALAXEV based on Bruzual & Charlot (2003).”
The VISTA deep extragalactic observations (VIDEO) survey (2012, methodology): “The AGN templates are those used and described in detail in Polletta et al. (2007), the library consists of empirically determined spectra for three Type 1 AGNs, five Type 2 AGNs and two composite AGNs and starburst galaxies.”
The X-ray to optical-UV luminosity ratio of X-ray selected type 1 AGN in XMM-COSMOS (2009, background): “…templates which include both normal galaxies (early type, late type and ULIRG galaxies), low-and-high luminosity QSOs (both Type 1 and 2) and hybrids created assum- ing a varying ratio between the AGN and a galaxy templates (90:10, 80:20,..., 10:90; see S09 for details and Polletta et al. 2007).”
Panchromatic spectral energy distributions of Herschel sources (2013, methodology): “8 show the same color-redshift tracks for the Polletta et al. (2007) template set.”
Tracing the cosmic growth of supermassive black holes to z ∼ 3 with Herschel (2014, methodology): “This curve is purely illustrative and it is taken from the SED template of IRAS 20551–4250, which is a local star-forming galaxy hosting an AGN (see Polletta et al. 2007).”
CHARACTERIZING THE MID-INFRARED EXTRAGALACTIC SKY WITH WISE AND SDSS (2012, methodology): “Figure 10 shows the W1 − W2 and W2 − W3 color tracks as a function of redshift calculated using the set of SED templates of Assef et al. (2010), the Arp 220 SED template of Polletta et al. (2007) and the IRAS15250+3609 template of Vega et al. (2008).”