X - ray properties of the Parkes sample of flat - spectrum radio sources : dust in radio - loud quasars ?
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چکیده
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 either determined with a hardness ratio technique or from direct fits to pointed PSPC data if a sufficient number of photons is available. The average photon index is Γ = 1.95
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تاریخ انتشار 1998