Physical conditions in active nuclei - III. Lyman beta and O VI lambda 1035 emission from QSOs.
Abstract
An emission line at approximately 1030 A in the spectrum of QSOs is investigated. Emission of Ly-beta by recombination in an optically thin atmosphere cannot explain this feature, as Ly-gamma, which would also appear, is not observed. Some contribution to the line may be due to Ly-beta leakage from a gas optically thick to Balmer-line radiation. The predicted intensity of the O VI 1035-A and other ultraviolet lines is computed with the aid of a photoionization model, and the O VI line is shown to have the observed intensity provided a large fraction of the quasar mass is concentrated in the center.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1976
- DOI:
- 10.1093/mnras/177.2.473
- Bibcode:
- 1976MNRAS.177..473N
- Keywords:
-
- Emission Spectra;
- Mass Distribution;
- Optical Thickness;
- Quasars;
- Red Shift;
- Astronomical Models;
- Astrophysics;
- Balmer Series;
- Photoionization;
- Radio Astronomy;
- Astrophysics