B/sub n/ factors at low temperatures
Abstract
High n-level populations (b/sub n/ factors) are calculated for temperatures ranging from 10 to 1000 K. The importance of collisions at pronounced quantum-number variations is analyzed and the collisions are found to affect appreciably the computed populations. Reasonable agreement with the results of Burgess and Summers (1976) and Brockhurst and Salem (1977) is established. It is shown that the infrared radiation field from a nearby H II region has only a small effect on the level populations.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 1979
- Bibcode:
- 1979A&A....80..325U
- Keywords:
-
- Atomic Energy Levels;
- Interstellar Matter;
- Low Temperature;
- Radio Spectra;
- Atomic Excitations;
- H Ii Regions;
- Particle Collisions;
- Radiative Recombination;
- Astrophysics