Evidence for absorption due to highly-ionized gas
in the radio-quiet quasar PG~1114+445
Authors:
George, I.M.,
Nandra, K.,
Laor, A.,
Turner, T.J.,
Fiore, F.,
Netzer, H.,
Mushotzky, R.F.
Journal: ApJ,
Publication Date: scheduled 1997 Dec 20
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 good agreement between all the datasets can be obtained if the
underlying continuum in the 0.2--10 keV band
is assumed to be a powerlaw (photon index
Gamma ~ 1.8) absorbed by photoionized material.
The ionized gas imprints deep absorption edges in the observed spectrum
<~ 2 keV due to Ovii and Oviii, from which we
determine its column density (~2E22 cm^2) and
ionization parameter (Ux~0.1) to be similar to that observed in
Seyfert-I galaxies.
Unfortunately these data do not allow any strong constraints to be placed on
the location, or solid angle subtended by the material at the
ionizing source.
We also find evidence for 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 out-flowing
from the nucleus.
We briefly compare our results with those obtained from other active galaxies.
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