The authors discuss numerical methods and algorithms for the solution of NLTE stellar atmosphere problems involving expanding atmospheres, e.g., found in novae, supernovae and stellar winds. They show how a scheme of nested iterations can be used to reduce the high dimension of the problem to a number of problems with smaller dimensions. As examples of these sub-problems, they discuss the numerical solution of the radiative transfer equation for relativistically expanding media with spherical symmetry, the solution of the multi-level nonLTE statistical equilibrium problem for extremely large model atoms, and their temperature correction procedure. Although modern iteration schemes are very efficient, parallel algorithms are essential in making large-scale calculations feasible, therefore they discuss some parallelization schemes that they have developed.
Journal of Computational and Applied Mathematics
- Pub Date:
- September 1999
- Stellar Atmospheres: Numerical Methods;
- Stellar Atmospheres: Radiative Transfer;
- JCAM, in press. 28 pages, also available at ftp://calvin.physast.uga.edu:/pub/preprints/CompAstro.ps.gz