ROSAT Deep X-Ray Radio Blazar Survey Catalog

ROSAT Deep X-Ray Radio Blazar Survey Catalog ROSAT/DXRBS ivo://nasa.heasarc/dxrbs NASA/GSFC HEASARC Perlman et al.; Landt et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The authors have undertaken a survey, the Deep X-Ray Radio Blazar Survey (DXRBS), of archived, pointed ROSAT Position Sensitive Proportional Counter (PSPC) data for blazars by correlating the ROSAT WGACAT database with several publicly available radio catalogs, restricting their candidate list to serendipitous flat radio spectrum sources (Alphar <= 0.70, where SNu ~ Nu-Alphar). In their first paper (DXRBS-I), the authors discuss their survey methods, identification procedure, and first results. Their survey was found to be 95% efficient at finding flat-spectrum radio-loud quasars (FSRQs; 59 of their first 85 identifications) and BL Lacertae objects (22 of their first 85 identifications), a figure that is comparable to or greater than that achieved by other radio and X-ray survey techniques. The identifications presented therein showed that all previous samples of blazars (even when taken together) did not representatively survey the blazar population, missing critical regions of (LX, LR) parameter space within which large fractions of the blazar population lie. Particularly important was the identification of a large population of FSRQs (>=25% of DXRBS-I FSRQs) with ratios of X-ray to radio luminosity >= 10-6 (Alpharx <= 0.78). In addition, as a result of their greater sensitivity, the DXRBS-I already more than doubled the number of FSRQs in complete samples with 5-GHz (radio) luminosities between 1031.5 and 1033.5 ergs/s/Hz, and filled in the region of parameter space between X-ray-selected and radio-selected samples of BL Lac objects. The DXRBS-I was the very first sample to contain statistically significant numbers of blazars at low luminosities, approaching what should be the lower end of the FSRQ luminosity function. In DXRBS-II, the authors presented new identifications and spectra for 106 sources, including 86 radio-loud quasars, 11 BL Lacertae objects, and nine narrow-line radio galaxies. Together with the DXRBS-I objects and already-known sources, their sample now contained 298 identified objects: 234 radio-loud quasars [181 flat-spectrum quasars: FSRQ (Alphar <= 0.50) and 53 steep-spectrum quasars: SSRQ], 36 BL Lacs and 28 narrow-line radio galaxies. Redshift information is available for 96 per cent of these. Thus, the selection technique was ~90 per cent efficient at finding radio-loud quasars and BL Lacs. Reaching 5-GHz radio fluxes of ~ 50 mJy and 0.1 - 2.0 keV X-ray fluxes of a few times 10-14 erg/cm2/s, DXRBS is the faintest and largest flat-spectrum radio sample with nearly complete (~85 per cent) identification. The DXRBS-I entries in this catalog (identified by having values of the parameter dxrbs_part equal to 1) contain data for 85 identified sources meeting the authors' selection criteria. A number of sources were serendipitously observed by ROSAT on more than one occasion, and, for completeness, the WGACAT positions and values for these multiply observed sources are listed separately, resulting in 102 DXRBS-I entries in this catalog (71 sources with 1 X-ray observation, 11 sources with 2 X-ray observations, and 3 sources with 3 X-ray observations). The DXRBS-II entries in this catalog (identified by having values of the parameter dxrbs_part equal to 2) contain data for 106 identified sources meeting the authors' selection criteria. A number of sources were serendipitously observed by ROSAT on more than one occasion, and, for completeness, the WGACAT positions and values for these multiply observed sources are listed separately. In one case (1WGA J0513.8+0156') the source was detected twice by ROSAT and there are two possible optical counterparts: there are 2 entries for each X-ray observation corresponding to the different conterparts, resulting in a total of 4 entries for this source. There are 92 DXRBS-II sources with 1 X-ray observation, 11 sources with 2 X-ray observations, 2 sources with 4 X-ray observations and 1 source with 5 X-ray observations) resulting in 127 DXRBS-II entries for 106 sources in this catalog. Four of the DXRBS-I objects (1WGA J0421.5+1433, 1WGA J0528.5-5820, 1WGA J1057.6-7724 and 1WGA J1222.6+2934) were also included in DXRBS-II as higher signal-to-noise ratio (S/N) spectra were available. Thus, in the sum of the 2 DXRBS parts presented here, there are 229 entries corresponding to 191 newly discovered sources. The 109 previously identified blazars, 97 of which were listed in Table 6 of DXRBS-I, are not included in this table. This table was created by the HEASARC in March 2012 based on the merger of files table3.dat and table4.dat from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/115/1253">CDS Catalog J/AJ/115/1253</a> (DXRBS-I) and files table4.dat and table5.dat from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/323/757">CDS Catalog J/MNRAS/323/757</a> (DXRBS-II). (Note that it does not include the list of 97 previously identified blazars given in table6.dat of the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/115/1253">CDS Catalog J/AJ/115/1253</a>.) The current DXRBS table replaced a previous version (ingested in March 1999) which included only the DXRBS-I tables 3 and 4. This is a service provided by NASA HEASARC . 2001MNRAS.323..757L https://heasarc.gsfc.nasa.gov/W3Browse/all/dxrbs.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=dxrbs& GET text/xml 180 99999 true 167.03208333 -77.80305556 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=dxrbs GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_dxrbs&Action=More+Options&Action=Parameter+Search&ConeAdd=1 ROSAT 0.0166666666666667 X-ray public dxrbs ROSAT Deep X-Ray Radio Blazar Survey Catalog name WGACAT 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.soft double nullable fx 0.1-2keV X-Ray Flux erg/s/cm^2 phot.flux;em.X-ray.soft double nullable flux_6_cm Radio Flux at 6 cm mJy phot.flux.density;em.radio.3-6GHz short nullable redshift Redshift src.redshift double nullable redshift_error RMS Uncertainty in Redshift stat.error;src.redshift double nullable redshift_flag Flag [?] Indicates Unknown Redshift meta.code;src.redshift char nullable ref_position Reference Code for Source meta.ref;pos char nullable rmag R Magnitude mag phot.mag;em.opt.R double nullable emag_limit Limit Flag for E Magnitude meta.code;phot.mag;em.opt.R char nullable off_axis PSPC Center Offset arcmin instr.offset double nullable optical_error_radius Optical Counterpart Position Error arcsec stat.error;pos;em.opt short nullable select_flag Flag [N] Indicates Source Does Not Meet Strict DXRBS Selection Criteria meta.code char nullable emag_flag Flag [n] Indicates Note Concerning E Magnitude meta.code;phot.mag;em.opt.R char nullable ra_radio PNM or GB6 Right Ascension degree pos.eq.ra;em.radio double nullable hardness_ratio ROSAT Hardness Ratio of Hard (0.87-2.0keV) and Medium (0.4-0.86keV) Count Rates phot.flux;arith.ratio;em.X-ray.soft double nullable other_catalogs Other Catalogs meta.ref char nullable spectral_index_flag Flag [n] Indicates Note Concerning Spectral Index meta.code;spect.index;em.radio char nullable spectral_index Radio Spectral Index spect.index;em.radio double nullable class Browse Object Classification src.class short nullable omag O-Plate (Blue) Magnitude (from APM) mag phot.mag;em.opt.B double nullable bmag_limit Limit Flag for B Magnitude meta.code;phot.mag;em.opt.B char nullable bj_mag_flag Flag [n] Indicates Note Concerning B_j Magnitude meta.code;phot.mag;em.opt.B char nullable omag_limit Limit Flag for O Magnitude meta.code;phot.mag;em.opt.B char nullable position_flag Flag [n] Indicates Note Concerning Position meta.code char nullable ra_optical Optical Right Ascension degree pos.eq.ra;em.opt double nullable source_flag Flag [n] Indicates Note Concerning Source meta.code;src char nullable fx_dens_1kev X-Ray Flux at 1 keV microJy phot.flux.density;em.X-ray.soft double nullable rmag_limit Limit Flag for R Magnitude meta.code;phot.mag;em.opt.R char nullable xray_opt_offset_sigma Ratio of Offset to Error pos.angDistance;arith.ratio double nullable omag_flag Flag [n] Indicates Note Concerning O Magnitude meta.code;phot.mag;em.opt.B char nullable entry_number Sequential Identification Number for Each Source in DXRBS I/II meta.id short nullable lii Galactic Longitude degree pos.galactic.lon double nullable error_radius WGACAT Error Radius arcsec stat.error;pos short nullable bmag B Magnitude mag phot.mag;em.opt.B double nullable emag E-Plate (Red) Magnitude (from APM) mag phot.mag;em.opt.R double nullable bj_mag B_j (Blue) Magnitude (from COSMOS) mag phot.mag;em.opt.B double nullable log_fx_flux_6_cm Logarithm of Radio(6cm)-to-X-Ray(0.3-3.65keV) Flux Ratio phot.flux;arith.ratio;em.X-ray;em.radio.3-6GHz double nullable dec_optical Optical Declination degree pos.eq.dec;em.opt double nullable dxrbs_part Number [12] Indicates Entry Belongs to Either DXRBS I or II meta.dataset short nullable dec_radio PNM or GB6 Declination degree pos.eq.dec;em.radio double nullable xray_opt_offset Offset Between X-Ray and Optical Positions arcsec pos.angDistance;em.X-ray;em.opt double nullable xray_opt_offset_error RMS Uncertainty in Offset Between X-Ray and Optical Positions arcsec stat.error;pos.angDistance;em.X-ray;em.opt double nullable bii Galactic Latitude degree pos.galactic.lat double nullable object_type Object 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