The Transfer of Resonance-Line Radiation in Static Astrophysical Media
Abstract
An analytic solution is derived for the mean intensity of resonance-line radiation within an absorbing medium of large scattering optical depth but low density. The line profile, the mean number of scatterings before absorption or escape, the mean path length traveled, and the fraction of the photons which escape the medium are derived. Approximate methods are also developed which permit the treatment of media of intermediate optical depth, where scattering takes place in the Doppler core. Astrophysical applications include the absorption of H Ly-alpha radiation by stellar dust, the pumping of H2 Lyman band lines by H Ly-alpha and the Bowen fluorescence.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1990
- DOI:
- 10.1086/168375
- Bibcode:
- 1990ApJ...350..216N
- Keywords:
-
- Hydrogen Atoms;
- Interstellar Gas;
- Radiative Transfer;
- Resonance Lines;
- Computational Astrophysics;
- Partial Differential Equations;
- Statics;
- Astrophysics;
- INTERSTELLAR: MATTER;
- LINE FORMATION;
- RADIATIVE TRANSFER