2D non-LTE modeling for axisymmetric winds

Abstract

Aims. This paper describes a code which is capable of modeling axisymmetric stellar winds. Methods. At present the code uses a short characteristic technique for the continuum transfer, while bound-bound transitions are treated using the Sobolev approximation. The simultaneous solution of the transfer equations, and the equations of statistical equilibrium, is achieved by a combination of preconditioning and linearization. Results. Extensive tests were performed which show that, in the extreme conditions of gray opacity or spherical symmetry, the code performs similar to other established codes. Simple 2D tests have been undertaken which confirm the performance of the code, and serve to illustrate simple effects that can occur in axisymmetric stellar winds. The code has been designed with flexibility in mind, with the radiation transport section treated, as far as possible, distinctly from the solution of the statistical equilibrium and energy balance equations. This will facilitate the inclusion of other transport solvers, and the treatment of more complex geometries.