PG 1416-129 : a broad absorption line QSO with low intrinsic X-ray absorption.
Abstract
A ROSAT PSPC spectrum of-the close broad absorption line (BAL)QSO PG 1416-129 is presented. The spectrum is very well fitted by a power law with spectral index α = 1.2 +/- 0.15. This is much steeper than the very flat spectrum (α = 0.1) found from earlier GINGA observations. The change in spectral slope occurs around 3 keV. We derive an upper limit on the column density of the broad absorption line region of 2 x 10^21^ cm^-2^ if the absorbing matter is assumed to have an ionization parameter at which significant amounts of the observed CIV and NV ions are present, and 10^20^cm^-2^ if it is cold. This low upper limit in combination with the large equivalent width of the BALs, constrains the ionization parameter in the BAL clouds and indicates that these clouds can not be very optically thick in the UV resonance lines of NV and CIV.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1994
- Bibcode:
- 1994A&A...281L..65D
- Keywords:
-
- Absorption Spectra;
- Line Spectra;
- Quasars;
- Resonance Lines;
- Spaceborne Astronomy;
- Ultraviolet Astronomy;
- Ultraviolet Spectra;
- X Ray Astronomy;
- X Ray Spectra;
- Astronomical Spectroscopy;
- Carbon;
- Ginga Satellite;
- Nitrogen;
- Power Series;
- Proportional Counters;
- Rosat Mission;
- Spectral Line Width;
- Stellar Spectra;
- Astronomy