Formation and transfer of permitted SI II emission lines in Seyfert I galaxies and quasars
Abstract
Results on the transfer of Si II emission lines in finite, optically thick, atmospheres of quasars and Seyfert I galaxies are presented. Intensities have been computed, giving exact solutions to the transfer, ionization equilibrium, and statistical equilibrium equations in an 11-level model ion. The absence of observed 3858 and 6355 lines sets upper limits on the total hydrogen column density (less than 10 to the 23rd/sq cm). Permitted ranges of the electron density, electron temperature, and total hydrogen column density are deduced for homogeneous models. Photoionized models (Netzer, 1980; Kwan and Krolik, 1979) are also examined; the temperature and/or radius of these models are found to be inconsistent with the Si II observed emission lines.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1981
- Bibcode:
- 1981A&A...102....1D
- Keywords:
-
- Astronomical Spectroscopy;
- Emission Spectra;
- Quasars;
- Seyfert Galaxies;
- Silicon;
- Astronomical Models;
- Brightness;
- Line Spectra;
- Photoionization;
- Radiative Transfer;
- Astronomy