STScI Preprint #1229

The Deep X-Ray Radio Blazar Survey (DXRBS)

We have undertaken a survey for blazars by correlating the ROSAT WGACAT database with publicly available radio catalogs, restricting our candidate list to serendipitous flat-spectrum sources (_r 0.7, f ^-). We discuss here our survey methods, identification procedure and first results. Our survey is found to be ~ 95% efficient at finding blazars, a figure which is comparable to or greater than that achieved by other radio and X-ray survey techniques. DXRBS provides a much more uniform coverage of the parameter space occupied by blazars than any previous survey. Particularly important is the identification of a large population of flat-spectrum radio quasars with ratios of X-ray to radio luminosity 10^-6 (_rx 0.78) and of many low-luminosity flat-spectrum radio quasars. Moreover, DXRBS fills in the region of parameter space between X-ray selected and radio-selected samples of BL Lacs.

Status:

Appeared in: Looking Deep in the Southern Sky, 187-193, 1999.

Affiliations:

¹) Space Telescope Science Institute, 3700 San Martin Drive, Baltimore MD. 21218, USA
²) Affiliated to the Astrophysics Division, Space Science Department, European Space Agency
³) On leave from Dipartimento di Fisica, II Università di Roma "Tor Vergata", Italy
⁴) SAX Science Data Center, ASI, Viale Regina Margherita 202, I-00198, Italy
⁵) Pennsylvania State University, Department of Astronomy, 525 Davey Lab, University Park, PA 16803
⁶) School of Physics & Astronomy, Univ. of Birmingham, Birmingham B15 2TT, UK
⁷) Australia Telescope National Facility, CSIRO, PO Box 76, Epping NSW 2121, Australia