CDFS1MS ivo://nasa.heasarc/chandfs1ms NASA/GSFC HEASARC Giacconi et al. 2026-10-02 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The Chandra Deep Field South (CDFS) 1-Megasecond Catalog is the source catalog obtained from a 942 kilosecond exposure, using the Advanced CCD Imaging Spectrometer (ACIS-I) on the Chandra X-ray Observatory. Eleven individual pointings made between 1999 October and 2000 December were combined to generate the final image used for object detection. Catalog generation proceeded simultaneously using two different methods: a method of the authors' own design using a modified version of the SExtractor algorithm, and a wavelet transform technique developed specifically for Chandra observations. The detection threshold was set in order to have less than 10 spurious sources, as assessed by extensive simulations. The catalog as published was subdivided into four sections: the primary list consisting of objects common to the two detection methods, two secondary lists containing sources which were detected by either the SExtractor algorithm alone or by the wavelet technique alone, and the fourth list consisting of possible diffuse or extended sources. The flux limits at the aimpoint for the soft (0.5 - 2 keV) and hard (2 - 10 keV) bands are 5.5 x 10<sup>-17</sup> erg/s/cm<sup>2</sup> and 4.5 x 10<sup>-16</sup> erg/s/cm<sup>2</sup>, respectively. The total number of sources is 346; out of them, 307 were detected in the 0.5 - 2 keV band, and 251 in the 2 - 10 keV band. Optical identifications are also presented for the catalogued sources. The primary optical data are R band imaging from VLT/FORS1 to a depth of R ~ 26.5 (Vega). In regions of the field not covered by the VLT/FORS1 deep imaging, the authors use R-band data obtained with the Wide Field Imager (WFI) on the ESO-MPI 2.2 m telescope, as part of the ESO Imaging Survey (EIS), which cover the entire X-ray survey. The FORS1/Chandra offsets are small, ~1 arcsecond. Coordinate cross-correlation finds 85% of the Chandra sources covered by FORS1 R to have counterparts within the 3-sigma error box (>~1.5 arcseconds, depending on off-axis angle and X-ray signal-to-noise). The unidentified fraction of sources, approximately 10% - 15%, is close to the limit expected from the observed X-ray flux to R-band ratio distribution for the identified sample. This online catalog was created by the HEASARC in June 2002 based on machine-readable versions of 2, 3 and 4 of Giacconi et al. (2002) that were obtained from the CDS. This is a service provided by NASA HEASARC . 2002ApJS..139..369G https://heasarc.gsfc.nasa.gov/W3Browse/all/chandfs1ms.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=chandfs1ms& GET text/xml 180 99999 true 53.126 -28.00621111 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=chandfs1ms GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_chandfs1ms&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public chandfs1ms Chandra Deep Field South 1-Megasecond Catalog name X-Ray 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 error_radius Error in X-ray Source Position (arcsec) arcsec stat.error;pos double nullable sb_counts Net Soft (0.5-2keV) Band Counts ct double nullable sb_counts_error Error in Soft Band Counts ct double nullable hb_counts Net Hard (2-10keV) Band Counts ct double nullable hb_counts_error Error in Hard Band Counts ct 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 sb_exposure Soft Band Exposure Time (s) s double nullable limit_rmag_1 Limit Flag for R Magnitude of 1st Counterpart char nullable optical_id Optical Identification Number (Not Unique) short nullable filter_rmag_3 Filter of the 3rd Optical Counterpart R Magnitude Observation [WF] char nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray.medium;em.X-ray.soft double nullable hb_flux_error Error in Hard Band Flux erg/cm^2/s double nullable offset_2 Separation with 2nd Candidate Optical Counterpart (arcsec) arcsec double nullable rmag_2_error Error on R Magnitude of 1st Counterpart mag double nullable hb_exposure Hard Band Exposure Time (s) s double nullable limit_hb_flux Limit Flag for Hard Band Flux char nullable hardness_ratio_error Error in Hardness Ratio stat.error;phot.flux;arith.ratio;em.X-ray.medium;em.X-ray.soft double nullable offset_1 Separation with 1st Candidate Optical Counterpart (arcsec) arcsec double nullable filter_rmag_2 Filter of the 2nd Optical Counterpart R Magnitude Observation [WF] char nullable rmag_2 Vega R Magnitude of 2nd Optical Counterpart mag double nullable rmag_1_error Error on R Magnitude of 1st Counterpart mag double nullable offset_3 Separation with 3rd Candidate Optical Counterpart (arcsec) arcsec double nullable hb_flux Hard Band Flux (erg/cm^2/s) erg/cm^2/s double nullable xray_id X-Ray Source Unique Detection Identification Number, [GZW2002] XID NNN in SIMBAD short nullable detect_method Method of Detection char nullable limit_rmag_3 Limit Flag for R Magnitude of 3rd Optical Counterpart char nullable rmag_3_error Error on R Magnitude of 3rd Optical Counterpart mag double nullable rmag_1 Vega R Magnitude of 1st Optical Counterpart mag double nullable sb_flux Soft Band Flux (erg/cm^2/s) erg/cm^2/s double nullable bii Galactic Latitude degree pos.galactic.lat double nullable filter_rmag_1 Filter of the 1st Optical Counterpart R Magnitude Observation [WF] char nullable sb_flux_error Error in Soft Band Flux erg/cm^2/s double nullable lii Galactic Longitude degree pos.galactic.lon double nullable rmag_3 Vega R Magnitude of 3rd Optical Counterpart mag double nullable limit_sb_flux Limit Flag for Soft Band Flux char nullable limit_rmag_2 Limit Flag for R Magnitude of 2nd Counterpart char nullable