XMM-Newton Large-Scale Structure Optical Counterparts and Redshifts

XMM-Newton Large-Scale Structure Optical Counterparts and Redshifts XMMLSSCLAS ivo://nasa.heasarc/xmmlssclas NASA/GSFC HEASARC Melnyk et al. 2026-07-17 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The XMM-Large Scale Structure (XMM-LSS) survey, covering an area of 11.1 square degrees, contains more than 6,000 X-ray point-like sources detected with the XMM-Newton Observatory to a flux of 3 x 10-15 erg/s/cm2 in the 0.5-2.0 keV band. The vast majority of these sources have optical (CFHTLS: Canada France Hawaii Telescope Legacy Survey), infrared (SWIRE: Spitzer Wide-area InfraRed Extragalactic legacy survey) InfraRed Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS), near-infrared (UKIDSS: UKIRT Infrared Deep Sky Survey) and/or ultraviolet (GALEX: Galaxy Evolution Explorer) counterparts. The authors wished to investigate the environmental properties of the different types of the XMM-LSS X-ray sources by defining their environment using the i'-band CFHTLS W1 catalog of optical galaxies to a magnitude limit of 23.5 magnitudes. They have classified 4,435 X-ray selected sources on the basis of their spectra, spectral energy distributions (SEDs), and X-ray luminosities, and estimated their photometric redshifts, which have a 4-11 band photometry with an accuracy of sigma[Deltaz/(1+zsp)] = 0.076, with 22.6% outliers for i' < 26 mag. The authors estimated the local overdensities of 777 X-ray sources that have spectro-z or photo-z calculated by using more than seven bands (accuracy of sigma[(Deltaz/(1+zsp)] = 0.061, with 13.8% outliers) within the volume-limited region defined by 0.1 <= z <= 0.85 and -23.5 < M_i'_ < -20. Although X-ray sources may be found in variety of environments, a high fraction (~55-60%), as verified by comparing with the random expectations, reside in overdense regions. The galaxy overdensities within which X-ray sources reside show a positive recent redshift evolution (at least for the range studied; z <~ 0.85). The authors also find that X-ray selected galaxies, when compared to AGN, inhabit significantly higher galaxy overdensities, although their spatial extent appear to be smaller than that of AGN. Hard AGN (harness ratios HR >= -0.2) are located in more overdense regions than soft AGN (HR < -0.2), which is clearly seen in both redshift ranges, although it appears to be stronger in the higher redshift range (0.55 < z < 0.85). Furthermore, the galaxy overdensities (with delta > 1.5, where delta is defined in equation (3) of the reference paper) within which soft AGN are embedded appear to evolve more rapidly compared to the corresponding overdensities around hard AGN. This table contains the spectroscopic and/or photometric redshifts for 4,206 X-ray selected sources in the XMM-LSS field which have optical counterparts and have been classified by the authors. This table was created by the HEASARC in September 2013 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/557/A81">CDS Catalog J/A+A/557/A81</a> file table2.dat This is a service provided by NASA HEASARC . 2013A&A...557A..81M https://heasarc.gsfc.nasa.gov/W3Browse/all/xmmlssclas.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=xmmlssclas& GET text/xml 180 99999 true 34.17837 -6.36565 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=xmmlssclas GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_xmmlssclas&Action=More+Options&Action=Parameter+Search&ConeAdd=1 XMM-NEWTON 0.0166666666666667 X-ray public xmmlssclas XMM-Newton Large-Scale Structure Optical Counterparts and Redshi name Source Designation (2XLSSd JHHMMSS.s+DDMMSSm) meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable redshift Spectroscopic Redshift src.redshift double nullable phot_redshift Photometric Redshift src.redshift.phot double nullable sb_lx X-Ray Luminosity in the Soft Band erg/s phys.luminosity;em.X-ray.soft double nullable hb_lx X-Ray Luminosity in the Hard Band erg/s phys.luminosity;em.X-ray.medium double nullable final_class Final Classification of the Source src.class char nullable ref_redshift Reference Code(s) for the Spectroscopic Redshift meta.ref;src.redshift char nullable class Browse Object Classification src.class short nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray double nullable phot_redshift_flag Rank of the Photometric Redshift meta.code;src.redshift.phot short nullable sed_class Classification According to SED src.class char nullable spectral_class Spectral Classification src.class char nullable dog_flag Boolean Flag [01] Indicates DOG Object meta.code;src short nullable bii Galactic Latitude degree pos.galactic.lat double nullable lii Galactic Longitude degree pos.galactic.lon double nullable redshift_flag Rank of the Spectroscopic Redshift meta.code;src.redshift short nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable