BHROSATOpt. ivo://nasa.heasarc/bhrfscid NASA/GSFC HEASARC Mickaelian et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the Byurakan/Hamburg/ROSAT Catalog (BHRC) of the optical identifications of X-ray sources. The BHRC includes all 2791 X-ray sources from the ROSAT Faint Source Catalog (ROSAT-FSC, CDS Catalog <IX/29>) with galactic latitude |b| >= 30 degrees, declination >= 0 degrees, and ROSAT PSPC count rate CR > 0.04 ct/s. The optical identifications were carried out using the Hamburg Quasar Survey (HQS) digitized spectroscopic plates, the DSS1 and DSS2 (blue, red, and IR) images, the MAPS photometric data, the USNO-B1.0 (for proper motion), the NVSS and FIRST radio, and the IRAS and 2MASS infrared catalogs. From the DSS images, positional, brightness, color, extension, variability, and proper-motion information, the optical-to-X-ray positional offsets were obtained and a morphological classification was made. Available SIMBAD and NED data were also utilized. Cross-correlations were made with AGN, white dwarf, and cataclysmic variable catalogs (322, 8 and 7 associations, respectively). The authors managed to identify 97% of the sources (2696/2791 sources) that are associated with 3202 optical objects. 2248 X-ray sources have a single optical counterpart, 144 have a double or multiple optical counterpart (binaries, galaxy groups, etc.), and 304 have ambiguous identifications (some of the latter might actually be blends of two X-ray sources that were not resolved by ROSAT). The QSOs and AGN represent the largest group of X-ray counterparts (56.2%); bright stars (including late-type stars, but excluding WDs and CVs) are counterparts for 33.2% of the sources, and bright galaxies and groups of galaxies comprise 9.2%. A number of close galaxy pairs (possibly interacting/merging galaxies) are found as counterparts for X-ray sources (3.0%), as well as 1.0% WDs and 0.4% CVs. The BHRC may be used for the selection and study of samples of the various classes of X-ray emitters: the table gives all the available multiwavelength data for the identified sources. This table was created by the HEASARC in June 2006 based on CDS table J/A+A/449/425/table1.dat This is a service provided by NASA HEASARC . 2006A&A...449..425M https://heasarc.gsfc.nasa.gov/W3Browse/all/bhrfscid.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=bhrfscid& GET text/xml 180 99999 true 323.18845833 0.02961111 0.0333333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=bhrfscid GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_bhrfscid&Action=More+Options&Action=Parameter+Search&ConeAdd=1 ROSAT 0.0333333333333333 X-ray public bhrfscid Byurakan/Hamburg/ROSAT Catalog of Optical IDs name ROSAT 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 ROSAT Count Rate ct/s phot.count;em.X-ray double nullable count_rate_error ROSAT Count Rate Error ct/s stat.error;phot.count;em.X-ray double nullable source_type Object Type Classification src.class 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 maps_omag MAPS O Magnitude mag phot.mag;em.opt double nullable usno_emag USNO-B1.0 E Magnitude (Mean of DSS1 Red and DSS2 Red) mag phot.mag;em.opt double nullable bii Galactic Latitude degree pos.galactic.lat double nullable usno_oe_color USNO-B1.0 O-E Color (Mean of DSS1 O-E and DSS2 O-E) mag phot.color;em.opt double nullable error_radius ROSAT Positional Error (arcsec) arcsec stat.error;pos short nullable maps_oe_color MAPS O-E Color Index mag phot.color;em.opt double nullable usno_omag USNO-B1.0 O Magnitude (Mean of DSS1 Blue and DSS2 Blue) mag phot.mag;em.opt double nullable alt_rosat_offset Non-Optical Association: Distance Between the Source and ROSAT Positions arcsec pos.angDistance double nullable off_set Distance Between Optical and X-Ray Positions arcsec pos.angDistance double nullable hardness_ratio_1 ROSAT Hardness Ratio 1 phot.count;em.X-ray double nullable cat_dss2_offset Optical Association: Distance Between the Catalog and DSS2 Red Positions arcsec pos.angDistance;em.opt double nullable class Browse Object Classification src.class short nullable hardness_ratio_2_error ROSAT Hardness Ratio 2 Error stat.error;phot.count;em.X-ray double nullable usno_imag USNO-B1.0 I Magnitude (DSS2 IR) mag phot.mag;em.opt.I double nullable hardness_ratio_2 ROSAT Hardness Ratio 2 phot.count;em.X-ray double nullable opt_name Optical Association: Name of the Object meta.id.assoc char nullable alt_name_band Detection Band of Association with Non-Optical Source (Radio, IR, Other X-Ray) meta.id.assoc;instr.bandpass char nullable cat_rosat_offset Optical Association: Distance Between the Catalog and ROSAT Positions arcsec pos.angDistance;em.X-ray double nullable lii Galactic Longitude degree pos.galactic.lon double nullable hardness_ratio_1_error ROSAT Hardness Ratio 1 Error stat.error;phot.count;em.X-ray double nullable redshift Optical Association: Redshift src.redshift double nullable app_mag Optical Association: Catalog Magnitude (Typically B Magnitude) mag phot.mag;em.opt.B double nullable alt_name Non-Optical Association: Name of the Source meta.id.assoc char nullable opt_ctrprt_component Optical Counterpart Component meta.id.assoc char nullable offset_error_radius Ratio of the Offset to the Error Radius stat.error;pos.angDistance double nullable pm_tot USNO-B1.0 Total Proper Motion mas/yr pos.pm short nullable other_source_type Associations with Known Optical Objects: Types src.class char nullable alt_dss2_offset Non-Optical Association: Distance Between the Source and DSS2 Red Positions arcsec pos.angDistance double nullable diff_usno_mag USNO-B1.0 Magnitude Difference Between DSS2 and DSS1 (Mean of Blue and Red) mag double nullable comments Comments on the Object meta.note char nullable app_mag_band Flag [BgR] Indicates Magnitude Band char nullable detailed_source_type Optical Association: Classification src.class char nullable