Chandra COSMOS (C-COSMOS) Survey X-Ray Point Source Catalog

Chandra COSMOS (C-COSMOS) Survey X-Ray Point Source Catalog CCOSMOSCAT ivo://nasa.heasarc/ccosmoscat NASA/GSFC HEASARC Elvis et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that has imaged the central 0.5 deg2 of the COSMOS field (centered at RA, Dec of 10 hours , +02 degrees) with an effective exposure of ~ 160 ks, and an outer 0.4 deg2 area with an effective exposure of ~ 80 ks. The limiting source detection depths are 1.9 x 10-16 erg cm-2 s-1 in the soft (0.5 - 2 keV) band, 7.3 x 10-16 erg cm-2 s-1 in the hard (2 - 10 keV) band, and 5.7 x 10-16 erg cm-2 s-1 in the full (0.5 - 10 keV) band. In this paper, the authors describe the strategy, design, and execution of the C-COSMOS survey, and present the catalog of 1761 point sources detected at a probability of being spurious of < 2 x 10-5 (1655 in the full, 1340 in the soft, and 1017 in the hard bands). By using a grid of 36 heavily (~ 50%) overlapping pointing positions with the ACIS-I imager, a remarkably uniform (+/-12%) exposure across the inner 0.5 deg2 field was obtained, leading to a sharply defined lower flux limit. The widely different point-spread functions obtained in each exposure at each point in the field required a novel source detection method, because of the overlapping tiling strategy, which is described in a companion paper. This method produced reliable sources down to a 7-12 counts, as verified by the resulting log N-log S curve, with sub-arcsecond positions, enabling optical and infrared identifications of virtually all sources, as reported in a second companion paper. Supporting data products for this table (including images, event files, and exposure maps) are available at the <a href="https://cosmos.astro.caltech.edu/page/xray/">COSMOS Survey website</a> and at <a href="https://irsa.ipac.caltech.edu/data/COSMOS/">IRSA</a>. At the IRSA website, it is also possible to search a database that includes "postage stamps" of the X-ray data for each source, along with the multi-wavelength optical and infrared data, including the I-band, K-band, and Spitzer 3.6-micron (Band 1) images used in the Part III paper (Civano et al. 2012) to identify the sources. See also the related table <a href="ccosmosoid.html">CCOSMOSOID</a> for the optical and infrared identifications of the surveyed X-ray point sources. This table was created by the HEASARC in November 2009 based on an electronic version of the C-COSMOS Catalog which was obtained from the Astrophysical Journal web site. This is a service provided by NASA HEASARC . 2009ApJS..184..158E https://heasarc.gsfc.nasa.gov/W3Browse/all/ccosmoscat.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=ccosmoscat& GET text/xml 180 99999 true 150.33663 1.601612 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=ccosmoscat GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_ccosmoscat&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public ccosmoscat Chandra COSMOS (C-COSMOS) Survey X-Ray Point Source Catalog name Chandra-COSMOS 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 count_rate Full 0.5-7 keV Count Rate ct/s phot.count;em.X-ray double nullable count_rate_error Error in Full 0.5-7 keV Count Rate ct/s stat.error;phot.count;em.X-ray double nullable flux Full 0.5-10 keV Flux; {gamma}=1.4 in erg/s/cm^2 erg/s/cm^2 phot.flux;em.X-ray double nullable flux_error Error in Full 0.5-10 keV Flux erg/s/cm^2 stat.error;phot.flux;em.X-ray double nullable hardness_ratio Hardness Ratio: (H-S)/(H+S) phot.flux;arith.ratio;em.X-ray double nullable sb_ap_exposure Soft 0.5-2 keV Exposure Time from Aperture Photometry (s) s time.duration;obs.exposure;em.X-ray.soft double nullable sb_count_rate Soft 0.5-2 keV Count Rate ct/s phot.count;em.X-ray.soft double nullable counts Full 0.5-7 keV Aperture Photometry Net Counts ct phot;em.X-ray double nullable counts_error Error in Full 0.5-7 keV Aperture Photometry Net Counts ct stat.error;phot;em.X-ray double nullable sb_exposure Soft 0.5-2 keV Exposure Time (s) s time.duration;obs.exposure;em.X-ray.soft double nullable sb_snr Soft 0.5-2 keV Signal-to-Noise stat.snr;em.X-ray.soft double nullable hb_counts_error Error in Hard 2-7 keV Aperture Photometry Net Counts ct stat.error;phot;em.X-ray.medium double nullable hb_count_rate_error Error in Hard 2-7 keV Count Rate ct/s stat.error;phot.count;em.X-ray.medium double nullable lii Galactic Longitude degree pos.galactic.lon double nullable hardness_ratio_pos_err Upper Uncertainty for Hardness Ratio (90%) stat.error;phot.flux;arith.ratio;em.X-ray double nullable sb_count_rate_error Error in Soft 0.5-2 keV Count Rate ct/s stat.error;phot.count;em.X-ray.soft double nullable hb_ap_exposure Hard 2-7 keV Exposure Time from Aperture Photometry (s) s time.duration;obs.exposure;em.X-ray.medium double nullable hb_counts Hard 2-7 keV Aperture Photometry Net Counts ct phot;em.X-ray.medium double nullable sb_flux_error Error in Soft 0.5-2 keV Flux erg/s/cm^2 stat.error;phot.flux;em.X-ray.soft double nullable hb_flux_error Error in Hard 2-10 keV Flux erg/s/cm^2 stat.error;phot.flux;em.X-ray.medium double nullable sb_flux Soft 0.5-2 keV Flux; {gamma}=1.4 in erg/s/cm^2 erg/s/cm^2 phot.flux;em.X-ray.soft double nullable sb_counts_error Error in Soft 0.5-2 keV Aperture Photometry Net Counts ct stat.error;phot;em.X-ray.soft double nullable ap_exposure Full 0.5-7 keV Exposure Time from Aperture Photometry (s) s time.duration;obs.exposure double nullable snr Full 0.5-7 keV Signal-to-Noise stat.snr;em.X-ray double nullable bii Galactic Latitude degree pos.galactic.lat double nullable source_number Sequential Identification Number for Each Source in Catalog meta.id;src int nullable hardness_ratio_neg_err Lower Uncertainty for Hardness Ratio (90%) stat.error;phot.flux;arith.ratio;em.X-ray double nullable hb_count_rate Hard 2-7 keV Count Rate ct/s phot.count;em.X-ray.medium double nullable hb_flux Hard 2-10 keV Flux; {gamma}=1.4 in erg/s/cm^2 erg/s/cm^2 phot.flux;em.X-ray.medium double nullable hb_exposure Hard 2-7 keV Exposure Time (s) s time.duration;obs.exposure;em.X-ray.medium double nullable sb_counts Soft 0.5-2 keV Aperture Photometry Net Counts ct phot;em.X-ray.soft double nullable error_radius Positional Uncertainty (arcsec) arcsec stat.error;pos double nullable hb_snr Hard 2-7 keV Signal-to-Noise stat.snr;em.X-ray.medium double nullable exposure Full 0.5-7 keV Exposure Time (s) s time.duration;obs.exposure double nullable alt_name Alternative Catalog-Based Source Designation meta.id char 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