Radio-loud and radio-quiet quasars observed by EXOSAT.

Abstract

We present results from the spectral analysis of EXOSAT data on 31 quasars, 18 radio-loud and 13 radio-quiet. Simple power-law models with fixed (Galactic) absorption give acceptable fits to the spectra obtained in the 2-10 keV band. Using the results from these fits we have compared the distributions of spectral indices α for the radio-loud and radio-quiet quasars in the sample. We find that the X-ray spectrum is flatter for radio-loud quasars, average α = 066 +/- 0.07, and is consistent with a single power-law index for these objects. The radio- quiet group, however, shows a steeper average spectrum, average α = 0.90 +/- 0.11, and a wider spread of indices.