J/AJ/115/1253 J/AJ/115/1253 Deep X-Ray Radio Blazar Survey E S Perlman P Padovani P Giommi R Sambruna L R Jones A Tzioumis J Reynolds Astron. J. 115 1253 1998 1998AJ....115.1253P IX/12 : The WGACAT version of ROSAT sources (White+ 1995) VIII/38 : The Parkes-MIT-NRAO 4.85GHz (PMN) Surveys (Griffith+ 1993-1996) VIII/40 : GB6 catalog of radio sources at 4.85GHz (Gregory+ 1996) VIII/15 : Parkes Radio Sources Catalogue (PKSCAT90) (Wright+ 1990) BL Lac objects QSOs Radio sources Surveys X-ray sources BL Lacertae objects: general quasars: general radio continuum surveys We have undertaken a survey, the Deep X-Ray Radio Blazar Survey (DXRBS), of archived, pointed ROSAT Position Sensitive Proportional Counter data for blazars by correlating the ROSAT WGACAT database with several publicly available radio catalogs, restricting our candidate list to serendipitous flat radio spectrum sources ({alpha}_r_<=0.70, where S_{nu}_{prop}{nu}^-{alpha}_r_^). We discuss our survey methods, identification procedure, and first results. Our survey is found to be 95% efficient at finding flat-spectrum radio-loud quasars (FSRQs; 59 of our first 85 identifications) and BL Lacertae objects (22 of our 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 here show 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 is the identification of a large population of FSRQs (>=25% of DXRBS FSRQs) with ratios of X-ray to radio luminosity >=10^-6^({alpha}_rx_<=0.78). In addition, as a result of our greater sensitivity, the DXRBS has already more than doubled the number of FSRQs in complete samples with 5GHz (radio) luminosities between 10^31.5^ and 10^33.5^ergs/s/Hz, and fills in the region of parameter space between X-ray-selected and radio-selected samples of BL Lac objects. The DXRBS is 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.

ROSAT

1WGA WGACAT name --- RAh WGACAT right ascension (J2000) h RAm WGACAT right ascension (J2000) min RAs WGACAT right ascension (J2000) s DE- WGACAT declination sign --- DEd WGACAT declination (J2000) deg DEm WGACAT declination (J2000) arcmin DEs WGACAT declination (J2000) arcsec oWGA Offset from field center in X-ray arcsec eWGA WGACAT error number=1 WGACAT positional error circles. This was done as follows: WGACAT was cross-correlated with the Hipparcos Input Catalogue (Cat. <I/196>), and the offsets between the two databases were obtained for six bins of the distance from the WGACAT field center (0'-10', 10'-20', etc.). These values range from 13" (for the inner 10' of the PSPC field) to 53" (for the 50'-60' ring). arcsec RA1h PMN or GB6 right ascension (J2000) h RA1m PMN or GB6 right ascension (J2000) min RA1s PMN or GB6 right ascension (J2000) s DE1- PMN or GB6 declination sign --- DE1d PMN or GB6 declination (J2000) deg DE1m PMN or GB6 declination (J2000) arcmin DE1s PMN or GB6 declination (J2000) arcsec RA2h Optical Counterpart right ascension (J2000) h RA2m Optical Counterpart right ascension (J2000) min RA2s Optical Counterpart right ascension (J2000) s DE2- Optical Counterpart declination sign --- DE2d Optical Counterpart declination (J2000) deg DE2m Optical Counterpart declination (J2000) arcmin DE2s Optical Counterpart declination (J2000) arcsec Source Source number=2 Source codes are: APM: APM survey GB6: Green Bank 6cm catalog, Cat. <VIII/40> PMN: Parkes-MIT-NRAO catalog, Cat. <VIII/27> ATCA: Austalian Telescope Compact Array, this paper NVSS: NRAO VLA Sky Survey, Condon et al., 1998AJ....115.1693C FIRST: FIRST project, Gregg et al., 1996AJ....112..407G; Laurent-Muehleisen et al., 1998, in prep. (see <VIII/51>) --- Offset Absolute offset (X-O) value arcsec eCount Counterpart error arcsec Error Cumulative error arcsec Offset/Error Ratio of Offset to Error --- 1WGA WGACAT name --- Crate ROSAT count rate ct/s F(0.1-2.0) 0.1-2.0keV flux mW/m2 F1keV Flux density at 1keV uJy log(FX/FR) X-flux to radio-flux ratio --- F6cm Flux density at 6cm mJy SI Radio spectral index --- l_Bmag Limit flag on Bmag --- Bmag B magnitude mag l_Rmag Limit flag on Rmag --- Rmag R magnitude mag Class Classification number=1 Classification is: RG: radio galaxy FSRQ: flat-spectrum radio-loud quasar SSRQ: steep-spectrum radio-loud quasar BL Lac: BL Lac object --- z Redsifht --- u_z Uncertainty flag on z --- Cat Other catalogs number=2 Other catalogs are numbered: 1: RASS Bright Source Catalog, Cat. <IX/10> 2: HBQS, Homogeneous Bright QSO Survey, Cat. <J/A+AS/112/347> 3: V Zwicky Catalog of Galaxies, Cat. <VII/190> 4: 4C, Fourth Cambridge Survey, Cat. <VIII/4> 5: Einstein Slew Survey, Elvis et al., 1992ApJS...80..257E 6: FIRST Bright Quasar Survey, See Cat. <VIII/51> 7: B3, Third Bologna Survey, Cat. <VIII/37> 8: Las Campanas Redshift Survey, Cat. <VII/203> --- Name Source name --- Crate ROSAT count rate ct/s F(0.1-2.0) 0.1-2.0keV flux mW/m2 F1keV Flux density at 1keV uJy log(FX/FR) X-flux to radio-flux ratio --- F6cm Flux density at 6cm mJy SI Radio spectral index --- Vmag V magnitude mag Class Classification number=1 Classification is: RG: radio galaxy FSRQ: flat-spectrum radio-loud quasar BL Lac: BL Lac object --- l_z Limit flag on z --- z Redsifht --- u_z Uncertainty flag on z --- 1WGA WGACAT name (repeated of more than 1 line) --- Note Text of the note --- Patricia Bauer CDS 1998Aug11 UNKNOWN UNKNOWN From AJ electronic version J_AJ_115_1253.xml