X-ray properties of the Parkes sample of flat-spectrum radio sources: dust in radio-loud quasars?

Abstract

We investigate the X-ray properties of the Parkes sample of flat-spectrum radio sources using data from the ROSAT All-Sky Survey and archival pointed PSPC observations. In total, 163 of the 323 sources are detected. For the remaining 160 sources, 2σ upper limits to the X-ray flux are derived. We present power-law photon indices in the 0.1–2.4 keV energy band for 115 sources, which were determined either with a hardness ratio technique or from direct fits to pointed PSPC data if a sufficient number of photons were available.