Composite models for the narrow emission line region of active galactic nuclei. V. The lines profiles.
Abstract
Kinematic line profiles are calculated on the basis of a new model of the narrow emission line region (NLR) in active galactic nuclei, which considers a distribution of emitting clouds with radial motion of different velocities. The line emission intensities from each cloud are provided by previous model calculations taking into account photoionization from the central zone of the active galaxy and shock effects. In the authors' model dust can easily survive in the intercloud medium rather than inside the clouds so that blueward shifts in line profiles from the NLR generally indicate an outward motion. Most of the analyzed objects present an observed profile that is well fitted by model calculations when the receding clouds emission is reduced by a factor <0.5, and an exponential distribution function on the cloud velocities is adopted. Moreover, calculated profiles show that "bumps", "tails" and "wings" can be different in the various lines of the same object.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1987
- Bibcode:
- 1987A&A...185...39C
- Keywords:
-
- Active Galactic Nuclei;
- Emission Spectra;
- Line Spectra;
- Seyfert Galaxies;
- Gas Density;
- Molecular Clouds;
- Astrophysics