The 1400 Å emission feature in quasi-stellar objects.
Abstract
Analysis of data for about 100 quasars allows the rest wavelength of the 1400-A emission feature to be determined to + or - 0.5 A rms, showing that the principal contributor (85 + or - 9% rms) is the semiforbidden O IV line at 1402.5 A, rather than the 1397-A emission line of Si IV. The observed strength of the feature is consistent with predictions of photoionization models and cosmic abundances of C, N, O, and Si if the collisional cross section of the 1402.5-A semiforbidden line of O IV is about three times the uncertain value in current use.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1979
- DOI:
- 10.1086/157358
- Bibcode:
- 1979ApJ...233....1W
- Keywords:
-
- Astronomical Spectroscopy;
- Emission Spectra;
- Quasars;
- Ultraviolet Astronomy;
- Astronomical Models;
- Line Spectra;
- Oxygen Spectra;
- Photoionization;
- Wavelengths;
- Astrophysics;
- Line Identifications:Quasi-Stellar Objects