Rapid nonLTE calculations of Balmer lines and hydrogen ionization  The solar case
Abstract
The authors propose an extremely rapid approximation method to determine a model of a planeparallel atmosphere in hydrostatic equilibrium given the temperature distribution, the gravity, and the chemical composition. The populations of the energy levels of hydrogen, the principal component, as well as its degree of ionization, are determined without the assumption of local thermodynamic equilibrium (nonLTE) by an approximation method based on the escape probability. The comparison of the results thus obtained with those of Vernazza et al. (1981) for their Model C is satisfactory for the Balmer lines and for ionization in the low chromosphere and in the photosphere.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 March 1985
 Bibcode:
 1985A&A...144..245D
 Keywords:

 Balmer Series;
 Hydrogen Ions;
 Nonequilibrium Thermodynamics;
 Solar Atmosphere;
 Solar Spectra;
 Approximation;
 H Alpha Line;
 Temperature Distribution;
 Solar Physics