SPICES Lynx Field Chandra X-Ray Source Catalog

SPICES Lynx Field Chandra X-Ray Source Catalog SPICESCXO ivo://nasa.heasarc/spicescxo NASA/GSFC HEASARC Stern et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the first results on field X-ray sources detected in a deep, 184.7 ks observation with the Advanced CCD Imaging Spectrometer (ACIS-I) on the Chandra X-Ray Observatory. The observations target the Lynx field (J2000.0 RA = 08h 48m and Dec = +44d 54') of SPICES, the Spectroscopic Photometric Infrared-Chosen Extragalactic Survey, which contains three known X-ray-emitting clusters at redshifts of z = 0.57, 1.26, and 1.27. Not including the known clusters, in the 17' x 17' ACIS-I field the authors detect 132 sources in the 0.5 - 2 keV (soft) X-ray band down to a 2.1-sigma limiting flux of ~ 1.7 x 10-16 erg/cm2/s and 11 sources in the 2 - 10 keV (hard) X-ray band down to a 2.1-sigma limiting flux of ~ 1.3 x 10-15 erg/cm2/s. The combined catalog contains a total of 153 X-ray sources, of which 42 are detected only in the soft band and 21 are detected only in the hard band. Confirming previous Chandra results, the authors find that the fainter sources have harder X-ray spectra, providing a consistent solution to the long-standing "spectral paradox". From deep optical and near-infrared follow-up data, 77% of the X-ray sources have optical counterparts to I = 24, and 71% of the X-ray sources have near-infrared counterparts to Ks = 20. Four of the 24 sources in the near-IR field are associated with extremely red objects (EROs; I - Ks >= 4). The authors have obtained spectroscopic redshifts with the Keck telescopes of 18 of the Lynx Chandra sources. These sources comprise a mix of broad-lined active galaxies, apparently normal galaxies, and two late-type Galactic dwarfs. Intriguingly, one Galactic source (number 72) is identified with an M7 dwarf exhibiting non-transient, hard X-ray emission. Thirteen of the Chandra sources are located within regions for which the authors have Hubble Space Telescope imaging. Nine of the sources are detected, showing a range of morphologies: several show compact cores embedded within diffuse emission, while others are spatially extended showing typical galaxy morphologies. Two of the Chandra sources in this subsample appear to be associated with mergers. ACIS-I observations of the Lynx field were obtained on 2000 May 3 (65 ks; OBS-ID 1708) and 2000 May 4 (125 ks; OBS-ID 927). Time intervals with background rates larger than 3 sigma over the quiescent value of ~ 0.30 counts s-1 per chip in the 0.3 - 10 keV band were removed. This procedure gave 60.7 ks of effective exposure out of the first observation and 124 ks out of the second, for a total of 184.7 ks. The two observations are almost coincident on the sky, so that the total coverage is 298 arcmin2. The aim point for the observations was RA = 08h 48m 54.79s, Dec = +44d 54' 32.9" (J2000.0), and both exposures were obtained in the faint mode when ACIS was at a temperature of -120 C. The Galactic absorbing column for this field is NH = 2 x 1020 cm-2. The position angle of the observations was 258.45 degrees. Cosmology-dependent parameters are calculated for two models: an Einstein-de Sitter (EdS) universe consistent with previous work in this field (H0 = 50 h50 km s-1 Mpc-1, OmegaM = 1, and OmegaLambda = 0) and the dark energy cosmology (DEC) universe favored by recent work on high-redshift supernovae and fluctuations in the cosmic microwave background (H0 = 65 km s-1 Mpc-1, OmegaM = 0.35, and OmegaLambda = 0.65). This table was created by the HEASARC in April 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/123/2223">CDS catalog J/AJ/123/2223</a> files table1.dat, table2.dat and table3.dat. This is a service provided by NASA HEASARC . 2002AJ....123.2223S https://heasarc.gsfc.nasa.gov/W3Browse/all/spicescxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=spicescxo& GET text/xml 180 99999 true 132.298875 44.74930556 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=spicescxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_spicescxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public spicescxo SPICES Lynx Field Chandra X-Ray Source Catalog name Catalog Source Designation 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 hb_counts Counts in the Hard Band (2-7keV) ct phot;em.X-ray.medium double nullable hb_counts_error RMS Uncertainty in the Hard-Band Counts ct stat.error;phot;em.X-ray.medium double nullable hb_flux Flux in the Hard Band (2-10 keV) (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray.medium double nullable imag Harris I-Band Magnitude mag phot.mag;em.opt.I double nullable redshift Spectroscopic Redshift src.redshift double nullable source_flag Flag [a] Indicates Host More Than 1.5 arcsec Away from Faint X-Ray Source meta.code char nullable rmag_flag Flag [:] Indicates Rmag Somewhat Affected by Nearby Stellar Bleed Trail meta.code;phot.mag;em.opt.R char nullable hardness_ratio Hardness Ratio (H-S)/(H+S) phot.flux;arith.ratio;em.X-ray.medium;em.X-ray.soft double nullable off_axis Distance of Source from Field Center (arcmin) arcmin instr.offset double nullable class Browse Object Classification src.class short nullable ks_mag The K_s-Band Magnitude mag phot.mag;em.IR.K double nullable optical_field_flag Flag [YN] Indicates Which X-Ray Sources Were Detected within the Optical Field meta.code char nullable source_type Galaxy Class or Spectral Type for Stars src.class char nullable abs_bmag_dec Lambda Rest-Frame Absolute B Magnitude mag phot.mag.bol;em.opt.B double nullable source_number Sequential Identification Number for Each X-Ray Source in Catalog meta.id short nullable sb_counts Counts in the Soft Band (0.5-2 keV) ct phot;em.X-ray.soft double nullable log_hb_lx_dec Lambda 2-10keV-Band Luminosity log(erg/s) phys.luminosity;em.X-ray.medium double nullable snr Signal-to-Noise Ratio of the X-Ray Detection stat.snr double nullable lii Galactic Longitude degree pos.galactic.lon double nullable dec_offset Declination Offset (arcsec) arcsec pos.angDistance double nullable sb_flux Flux in the Soft Band (0.5-2 keV) (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray.soft double nullable log_sb_lx_eds EdS 0.5-2keV-Band Luminosity log(erg/s) phys.luminosity;em.X-ray.soft double nullable jmag The J-Band Magnitude mag phot.mag;em.IR.J double nullable spices_id The SPICES Identification meta.id.assoc char nullable zmag The RG850 Long-Pass z-Band Magnitude mag phot.mag;em.opt double nullable sb_counts_error RMS Uncertainty in the Soft-Band Counts ct stat.error;phot;em.X-ray.soft double nullable bmag Harris B-Band Magnitude mag phot.mag;em.opt.B double nullable log_hb_lx_eds EdS 2-10keV-Band Luminosity log(erg/s) phys.luminosity;em.X-ray.medium double nullable log_sb_lx_dec Lambda 0.5-2keV-Band Luminosity log(erg/s) phys.luminosity;em.X-ray.soft double nullable bii Galactic Latitude degree pos.galactic.lat double nullable ra_offset Right Ascension Offset (arcsec) arcsec pos.angDistance double nullable rmag Harris R-Band Magnitude mag phot.mag;em.opt.R char nullable abs_bmag_eds EdS Rest-Frame Absolute B Magnitude mag phot.mag.bol;em.opt.B double 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