A search for X-ray absorbed sources in the 3XMM catalogue, using photometric redshifts and Bayesian spectral fits

Abstract

Since its launch in 1999, the XMM-\textit{Newton} mission has compiled the largest catalogue of serendipitous X-ray sources, with the 3XMM being the third version of this catalogue. This is because of the combination of a large effective area (5000 $\mathrm{c}{\mathrm{m}}^2$ at 1 keV) and a wide field of view (30 arcmin). The 3XMM-DR6 catalogue contains about 470,000 unique X-ray sources over an area of 982 $\mathrm{de}{\mathrm{g}}^2$. A significant fraction of these (100,178 sources) have reliable optical, near/mid-IR counterparts in the SDSS, PANSTARRS, VIDEO, UKIDSS and WISE surveys. In a previous paper we have presented photometric redshifts for these sources using the TPZ machine learning algorithm. About one fourth of these (22,677) have adequate photon statistics so that a reliable X-ray spectrum can be extracted. Obviously, owing to both the X-ray counts selection and the optical counterpart constraint, the sample above is biased towards the bright sources. Here, we present XMMFITCAT-Z: a spectral fit catalogue for these sources using the Bayesian X-ray Analysis (BXA) technique. As a science demonstration of the potential of the present catalogue, we comment on the optical and mid-IR colours of the 765 X-ray absorbed sources with $N_{\mathrm{H}}>10^{22}{\mathrm{cm}}^{-2}$. We show that a considerable fraction of X-ray selected AGN would not be classified as AGN following the mid-IR W1-W2 vs. W2 selection criterion. These are AGN with lower luminosities, where the contribution of the host galaxy to the MIR emission is non-negligible. Only one third of obscured AGN in X-rays present red colours or r-W2 > 6. Then it appears that the r-W2 criterion, often used in the literature for the selection of obscured AGN, produces very different X-ray absorbed AGN samples compared to the standard X-ray selection criteria.

arXiv comment12 pages, 10 figures. Reproduced with permission from Astronomy & Astrophysics, \c{opyright} ESO

References in corpus (38)

• Planck 2015 results. XIII. Cosmological parameters
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• Mid-Infrared Selection of Active Galaxies
• Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science
• Mid-Infrared Selection of AGN with the Wide-Field Infrared Survey Explorer. I. Characterizing WISE-Selected AGN in COSMOS
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• Identifying Luminous AGN in Deep Surveys: Revised IRAC Selection Criteria
• Broad iron lines in Active Galactic Nuclei
• Mid-Infrared Selection of Active Galactic Nuclei with the Wide-Field Infrared Survey Explorer. II. Properties of WISE-Selected Active Galactic Nuclei in the NDWFS Boötes Field
• The Spectral Energy Distributions of Low-Luminosity Active Galactic Nuclei
• A Model for the X-Ray and UV Emission from Seyfert Galaxies and Galactic Black Holes
• The XMM-Newton serendipitous survey. VII. The third XMM-Newton serendipitous source catalogue
• Using the Bright Ultra-Hard XMM-Newton Survey to define an IR selection of luminous AGN based on WISE colours
• TPZ : Photometric redshift PDFs and ancillary information by using prediction trees and random forests
• Spitzer Power-law AGN Candidates in the Chandra Deep Field-North
• Characterizing the Mid-IR Extragalactic Sky with WISE and SDSS
• X-ray Absorption and Reflection in Active Galactic Nuclei
• Exploring the X-ray Sky with the XMM-Newton Bright Serendipitous Survey
• A Spectroscopic Survey of X-ray Selected AGN in the Northern XMM-XXL Field
• Mid-infrared properties of X-ray sources in the Extended Groth Strip
• Uncovering obscured luminous AGN with WISE
• Harold Jeffreys's Theory of Probability Revisited
• A Comparison of X-ray and Mid-Infrared Selection of Obscured AGN
• Probabilistic multi-catalogue positional cross-match
• Does the obscured AGN fraction really depend on luminosity?
• Composite Spectral Energy Distributions and Infrared-Optical Colors of Type 1 and Type 2 Quasars
• An obscured AGN population hidden in the VIPERS galaxies: identification through spectral energy distribution decomposition
• The Soft X-ray Spectrum of Scattering--Dominated AGN
• XMMPZCAT: A catalogue of photometric redshifts for X-ray sources
• Searching for luminous absorbed sources in the WISE AGN catalogue
• XMMFITCAT: The XMM-Newton spectral-fit database
• Searching for highly obscured AGN in the XMM-Newton serendipitous source catalog
• Estimating Photometric Redshifts for X-ray sources in the X-ATLAS field, using machine-learning techniques
• Forward modeling the multiwavelength properties of Active Galactic Nuclei: application to X-ray and WISE mid-infrared samples
• Obscuration properties of mid-IR selected AGN

Cited by in corpus (7)

• AGN X-ray luminosity function and absorption function in the Early Universe ($3\le z\le 6$)
• The incidence of AGN in galaxies with different stellar population ages
• AGN populations in the local universe: their alignment with the main-sequence, characteristics of their stellar populations, accretion efficiency, and the impact of AGN feedback
• Influence of Comptonization region over the ambiance of accretion disc in Active Galactic Nucleus
• Harnessing the XMM-Newton data: X-ray spectral modelling of 4XMM-DR11 detections and 4XMM-DR11s sources
• Reconstructing AGN X-ray spectral parameter distributions with Bayesian methods I: Spectral analysis
• Selection of Compton-thick AGN from a hard photometric sample using XMM-Newton observations