The structure, shape, and evolution of radiatively accelerated QSO emission-line clouds.
Abstract
A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The structure, size and shape of QSO clouds are calculated, with special emphasis on the intimate connection between these intrinsic cloud parameters and the overall dynamic evolution of the clouds, which governs the shape of the emitted line profile. The calculations presented are not accurate hydrodynamical results but depend on a variety of simplifying assumptions, of which the most important is that the clouds remain stable and do not break up as they traverse the emission-line region. It is shown that the condition for constant cloud mass in the cloud frame is equivalent to the equation of motion of a cloud in the rest frame of the QSO. Finally, the covering factor of a system of pancake clouds and the total number of clouds required in a QSO are estimated.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1979
- DOI:
- 10.1086/157408
- Bibcode:
- 1979ApJ...233..479B
- Keywords:
-
- Cloud Physics;
- Galactic Nuclei;
- Interstellar Gas;
- Plasma Clouds;
- Quasars;
- Stellar Evolution;
- Acceleration (Physics);
- Astronomical Models;
- Cross Sections;
- Emission Spectra;
- Equations Of Motion;
- Galactic Evolution;
- Galactic Radiation;
- Line Spectra;
- Pressure Drag;
- Astrophysics;
- Active Galactic Nuclei;
- Emission Lines:Quasars