1997/08/04 by I. M. George, K. Nandra, A. Laor +4 · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/304998
Accepted for publication in ApJ (scheduled 1997 Dec 20), LaTeX, 18 pages
arxiv created 1997/08/04 · openalex publication_date 1997/12/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
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 × 10 22 cm -2 ) and ionization parameter ( U X ~ 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.