Core saturation in a moving mediumA numerical technique for solving the line transfer equation of a two-level atom in static equilibrium is presented. Complete redistribution of emitted photons is assumed, as is saturation at the line core. Emission intensity is calculated either by a generalized Eddington-Barber relation, a first-order differential equation for the specific intensity, or by a formal transfer integral. Sample calculations are performed of the line transfer equation in a semi-infinite atmosphere with a constant Planck function of the collision parameter and for the Mg II resonance line in a model solar atmosphere experiencing shocks. Attention is focused on the line wings in the latter problem. The first order differential equation approach yields the best intensity values and temperature structure.
Document ID
19850033979
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Kalkofen, W. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Ulmschneider, P. (Heidelberg, Universitaet Heidelberg, Germany)