Properties of the continua of eight PG QSOs from ASCA data

We have analyzed the continua of eight PG QSOs, obtained by the ASCA SIS detector with a higher energy resolution and a broader band than by ROSAT/PSPC and attempted to fit the data with a single power law, a double power law and a truncated power law. Four of the objects exhibit soft X excess in 0.4 – 10 keV. They are Mkn 478, PG 1444+407, PG 1543+48 and 3C 273. Furthermore, the ratio of the excess to total flux is the smaller, the greater the optical luminosity is. The presence or otherwise of the soft X-ray excess is unrelated to the radio properties and luminosity of the object.