The XMM-Newton survey of the ELAIS-S1 field II: optical identifications and multiwavelength catalogue of X-ray sources

Abstract

We present optical identifications and a multi-band catalogue of a sample of 478 X-ray sources in the XMM and Chandra surveys of the central 0.6 deg^2 of the ELAIS-S1 field. The optical/infrared counterpart of each X-ray source was identified using R and IRAC 3.6 um bands. This method was complemented by the precise positions obtained through Chandra observations. Approximately 94% of the counterparts are detected in the R band, while the remaining are blank fields in the optical down to R~24.5, but have a near-infrared counterpart detected by IRAC within 6 arcsec from the XMM centroid. The multi-band catalogue contains photometry in ten photometric bands (B to the MIPS 24 um). We determined redshift and classification for 237 sources (~50% of the sample) brighter than R=24. We classified 47% of the sources with spectroscopic redshift as broad-line active galactic nuclei (BL AGNs) with z=0.1-3.5, while sources without broad-lines are about 46% of the spectroscopic sample and are found up to z=2.6. We identified 11 type 2 QSOs among the sources with X/O>8, with z=0.9-2.6, high 2-10 keV luminosity (log(L2-10keV)>=43.8 erg/s) and hard X-ray colors suggesting large absorbing columns at the rest frame (logN_H up to 23.6 cm^-2). BL AGNs show on average blue optical-to-near-infrared colors, softer X-ray colors and X-ray-to-optical colors typical of optically selected AGNs. Conversely, narrow-line sources show redder optical colors, harder X-ray flux ratio and span a wider range of X-ray-to-optical colors. On average the SEDs of high-luminosity BL AGNs resemble the power-law typical of unobscured AGNs. The SEDs of NOT BL AGNs are dominated by the galaxy emission in the optical/near-infrared, and show a rise in the mid-infrared which suggests the presence of an obscured active nucleus.

arXiv comment15 pages, A&A accepted, affiliations corrected

References in corpus (39)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• The many lives of active galactic nuclei: cooling flows, black holes and the luminosities and colours of galaxies
• A Relationship Between Nuclear Black Hole Mass and Galaxy Velocity Dispersion
• Energy input from quasars regulates the growth and activity of black holes and their host galaxies
• Cosmological Evolution of the Hard X-ray AGN Luminosity Function and the Origin of the Hard X-ray Background
• A Physical Model for the Co-evolution of QSOs and of their Spheroidal Hosts
• Mid-Infrared Selection of Active Galaxies
• Spectral Energy Distributions of Hard X-ray selected AGNs in the XMDS Survey
• SWIRE: The SIRTF Wide-area InfraRed Extragalactic Survey
• Obscured and unobscured active galactic nuclei in the Spitzer Space Telescope First Look Survey
• Deep Extragalactic X-ray Surveys
• Observations of Ultraluminous Infrared Galaxies with the Infrared Spectrograph on the Spitzer Space Telescope II: The IRAS Bright Galaxy Sample
• The HELLAS2XMM survey. VII. The hard X-ray luminosity function of AGN up to z=4: more absorbed AGN at low luminosities and high redshifts
• Multiwavelength study of massive galaxies at z~2. II. Widespread Compton thick AGN and the concurrent growth of black holes and bulges
• Number Counts At 3 < lambda < 10 um From the Spitzer Space Telescope
• The HELLAS2XMM survey: IV. Optical identifications and the evolution of the accretion luminosity in the Universe
• Spectroscopic Redshifts to z > 2 for Optically Obscured Sources Discovered with the Spitzer Space Telescope
• Joint Formation of QSOs and Spheroids: QSOs as clocks of star formation in Spheroids
• Unveiling obscured accretion in the Chandra Deep Field South
• The VVDS data reduction pipeline: introducing VIPGI, the VIMOS Interactive Pipeline and Graphical Interface
• The XMM-Newton wide-field survey in the COSMOS field: III. optical identification and multiwavelength properties of a large sample of X-ray selected sources
• First Insights into the SWIRE Galaxy Populations
• Photometric redshifts and selection of high redshift galaxies in the NTT and Hubble Deep Fields
• The HELLAS2XMM survey: II. Multiwavelength observations of P3: an X-ray bright, optically inactive galaxy
• The Abundance of Distant and Extremely Red Galaxies: The Role of AGN Feedback in Hierarchical Models
• Connecting the cosmic infrared background to the X-ray background
• The HELLAS2XMM survey: VI. X-ray absorption in the 1dfAGN sample through a spectral analysis
• AGN and Starburst Classification from Spitzer Mid-Infrared Spectra for High Redshift SWIRE Sources
• XMM-Newton observations of Extremely Red Objects and the link with luminous, X-ray obscured Quasars
• Elusive AGN in the XMM-Newton bright serendipitous survey
• The XMM-Newton survey of the ELAIS-S1 field. I: Number counts, angular correlation function and X-ray spectral properties
• The HELLAS2XMM survey. V. Near-Infrared observations of X-ray sources with extreme X/O ratios
• The Serendipitous Extragalactic X-Ray Source Identification (SEXSI) Program. III. Optical Spectroscopy
• The nature of the mid-infrared population from optical identifications of the ELAIS-S1 sample
• The HELLAS2XMM survey. X. The bolometric output of luminous obscured quasars: The Spitzer perspective
• The ESO-Spitzer Imaging extragalactic Survey (ESIS) I: WFI B,V,R deep observations of ELAIS-S1 and comparison to Spitzer and GALEX data
• The HELLAS2XMM survey.VIII. Optical identifications of the extended sample
• The HELLAS2XMM survey: XI. Unveiling the nature of X-ray Bright Optically Normal Galaxies

Cited by in corpus (19)

• PRIMUS: The dependence of AGN accretion on host stellar mass and color
• The XMM-Newton Wide-Field Survey in the COSMOS field (XMM-COSMOS): demography and multiwavelength properties of obscured and unobscured luminous AGN
• The Spitzer Extragalactic Representative Volume Survey (SERVS): survey definition and goals
• HELP: The Herschel Extragalactic Legacy Project
• The M_BH - M_star relation for X-ray obscured, red QSOs at 1.2< z <2.6
• Revealing X-ray obscured quasars in SWIRE sources with extreme mid-IR/optical flux ratios
• The XMM-SERVS survey: XMM-Newton point-source catalogs for the W-CDF-S and ELAIS-S1 fields
• Tools for computing the AGN feedback: radio-loudness distribution and the kinetic luminosity function
• On the AGN radio luminosity distribution and the black hole fundamental plane
• Optical identification of XMM sources in the CFHTLS
• The Subaru-XMM-Newton Deep Survey (SXDS) VIII.: Multi-wavelength Identification, Optical/NIR Spectroscopic Properties, and Photometric Redshifts of X-ray Sources
• The QUEST-La Silla AGN Variability Survey: selection of AGN candidates through optical variability
• The M_BH-M_star relation of obscured AGNs at high redshift
• The Chandra Deep Group Survey -- cool core evolution in groups and clusters of galaxies
• Spectroscopic identifications of Spitzer sources in the SWIRE/XMM-NEWTON/ELAIS-S1 field: a large fraction of Active Galactic Nuclei with high F(24micron)/F(R) ratio
• AGN triggering in the infall regions of distant X-ray luminous galaxy clusters at 0.9 < z <~ 1.6
• The SWIRE/Chandra Survey: The X-ray Sources
• A systematic cross-search for radio/infrared counterparts of XMM-Newton sources
• X-Ray bright optically faint active galactic nuclei in the Subaru Hyper Suprime-Cam wide survey