Far ultraviolet line profiles in the Seyfert galaxy NGC 4151.
Abstract
Two high-resolution far-UV spectra (1150-2000 A) of the Seyfert 1 galaxy NGC 4151 are presented which were obtained from the IUE satellite with a resolution of about 10,000. It is found that the Ly-alpha line in NGC 4151 is asymmetric and rather narrow, that the Ly-alpha/H-beta ratio varies across the line, and that there are two absorption systems, one narrow and one broad, with the narrow component probably originating in the undisturbed outer parts of NGC 4151. The C IV emission doublet at 1550 A is shown to be considerably broader than the Ly-alpha line, and two alternative explanations are suggested for the details of the C IV absorption profile. Attention is also given to the C III semiforbidden line at 1909 A, several weaker absorption features, and observed spectral variations. It is concluded that the spectrum of NGC 4151 perhaps most closely resembles those of broad-emission-line quasars.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 1979
- DOI:
- 10.1093/mnras/189.1.45P
- Bibcode:
- 1979MNRAS.189P..45P
- Keywords:
-
- Astronomical Spectroscopy;
- Far Ultraviolet Radiation;
- Line Spectra;
- Seyfert Galaxies;
- Ultraviolet Astronomy;
- Ultraviolet Spectra;
- Absorption Spectra;
- Carbon;
- Emission Spectra;
- Iue;
- Lyman Alpha Radiation;
- Astrophysics;
- Seyfert Galaxies:UV Spectra