LALABOOCXO ivo://nasa.heasarc/lalaboocxo NASA/GSFC HEASARC Wang et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the results of an analysis of a deep, 172 ks Chandra observation of the Large Area Lyman Alpha survey (LALA) Bootes field which was obtained with the Advanced CCD Imaging Spectrometer (ACIS-I) on board the Chandra X-Ray Observatory. This is one of the deepest Chandra images of the extragalactic sky, with only the 2 Ms Chandra Deep Field North (CDF-N) and the 1 Ms Chandra Deep Field South (CDF-S) observations being substantially deeper. In this table, the X-ray source catalog obtained from this image is presented, along with some results from an analysis of the X-ray source counts and optical identifications. The X-ray image is composed of two individual observations obtained in 2002 and reaches 0.5 - 2.0 and 2.0 - 10.0 keV flux limits of 1.5 x 10<sup>-16</sup> and 1.0 x 10<sup>-15</sup> ergs/cm<sup>2</sup>/s, respectively, for point sources near the aim point. A total of 168 X-ray sources were detected: 160 in the 0.5 - 7.0 keV band, 132 in the 0.5 - 2.0 keV band, and 111 in the 2.0 - 7.0 keV band. Since X-ray source number 122 has two possible optical counterparts, it is listed twice, once for each counterpart, and the total number of entries in this table is this 169. The primary optical data are R-band imaging from the NOAO Deep Wide-Field Survey (NDWFS), with a limiting magnitude of R = 25.7 magnitudes, (Vega, 3-sigma detection level, and a 4" diameter aperture). Optical counterparts within 1.5" or the 3-sigma X-ray positional uncertainties, whichever was larger, were detected above this level in the R band for 144 of the 168 X-ray sources. At least 90% of the optical counterparts should be the correct matches, and, at worst, there might be ~14 false matches. This table was created by the HEASARC in March 2007 based on the CDS table J/AJ/127/213 file table1.dat, This is a service provided by NASA HEASARC . 2004AJ....127..213W https://heasarc.gsfc.nasa.gov/W3Browse/all/lalaboocxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=lalaboocxo& GET text/xml 180 99999 true 216.35166667 35.42836111 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=lalaboocxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_lalaboocxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public lalaboocxo LALA Bootes Field Chandra X-Ray Point Source Catalog name IAU Designation (Based on J2000 Position) meta.id char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable error_radius The 3-Sigma Centroid Position Uncertainty (arcsec) arcsec stat.error;pos double nullable fb_counts Net Total (0.5-7.0keV) Counts ct double nullable fb_counts_pos_err Upper 1-Sigma Poisson Uncertainty in Total Counts ct double nullable fb_counts_neg_err Lower 1-Sigma Poisson Uncertainty in Total Counts ct double nullable rmag_limit The 3-Sigma Limit Flag for Rmag char nullable rmag The R Band AUTO Magnitude mag phot.mag;em.opt.R double nullable rmag_error The 1-Sigma Uncertainty in Rmag mag stat.error;phot.mag;em.opt.R double nullable bii Galactic Latitude degree pos.galactic.lat double nullable lii Galactic Longitude degree pos.galactic.lon double nullable sb_flux The 0.5-2 keV X-Ray Flux (erg/s/cm^2) erg/s/cm^2 double nullable sb_counts_pos_err Upper 1-Sigma Poisson Uncertainty in Soft Counts ct double nullable sb_counts Net Soft (0.5-2.0keV) Counts ct double nullable dec_offset Optical Counterpart Declination Offset from X-Ray Position (arcsec) arcsec pos.angDistance double nullable fb_flux The 0.5-10 keV X-Ray Flux (erg/s/cm^2) erg/s/cm^2 double nullable hb_flux_limit Limit Flag for 2-10 keV X-Ray Flux char nullable ra_offset Optical Counterpart Right Ascension Offset from X-Ray Position (arcsec) arcsec pos.angDistance double nullable detection_bands Band of Source Detection char nullable alt_name Alternate Source Designation meta.id char nullable hb_counts_pos_err Upper 1-Sigma Poisson Uncertainty in Hard Counts ct double nullable rmag_flag Flag [ab] Indicates Overlapping in Rmag char nullable hb_counts Net Hard (2.0-7.0keV) Counts ct double nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray.medium;em.X-ray.soft double nullable opt_ctrprt_fwhm Optical Counterpart Full-Width Half-Maximum in R-Band Image arcsec double nullable hb_counts_neg_err Lower 1-Sigma Poisson Uncertainty in Hard Counts ct double nullable sb_flux_limit Limit Flag for 0.5-2 keV X-Ray Flux char nullable sb_counts_neg_err Lower 1-Sigma Poisson Uncertainty in Soft Counts ct double nullable hardness_ratio_neg_err Lower 1-Sigma Poisson Uncertainty in the Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray.medium;em.X-ray.soft double nullable source_number Sequential Identification Number for Each X-Ray Source in Catalog meta.id;meta.main short nullable hardness_ratio_pos_err Upper 1-Sigma Poisson Uncertainty in the Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray.medium;em.X-ray.soft double nullable hb_flux The 2-10 keV X-Ray Flux (erg/s/cm^2) erg/s/cm^2 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