Evidence of Absorption Due to Highly Ionized Gas in the Radio‐quiet Quasar PG 1114+445

Abstract

We present results on the X-ray spectrum of the quasar PG 1114+445 from an ASCA observation performed in 1996 June and a ROSAT observation performed 3 years earlier. We show that good agreement between all the data sets can be obtained if the underlying continuum in the 0.2-10 keV band is assumed to be a power law (photon index Γ 1.8) absorbed by photoionized material. The ionized gas imprints deep absorption edges in the observed spectrum 2 keV due to O VII and O VIII, from which we determine its column density (~2 × 1022 cm-2) and ionization parameter (UX ~ 0.1) to be similar to that observed in Seyfert 1 galaxies. Unfortunately, these data do not allow any strong constraints to be placed on the location of or the solid angle subtended by the material at the ionizing source. We also find evidence of absorption in the Fe K-shell band in excess of that predicted from the lower energy features. This implies an Fe/O abundance ratio ~10 times the cosmic value, or an additional screen of more highly ionized gas, possibly outflowing from the nucleus. We briefly compare our results with those obtained from other active galaxies.