Photon escape probabilities in expanding atmospheres

Abstract

A comparison of mean number of scatterings and escape probabilities has been made in isotropic scattering and dipole scattering by using the angle-averaged partial frequency redistribution functionR _I. We have solved the equations of radiative transfer and statistical equilibrium simultaneously in a spherically symmetric expanding atmosphere. Two cases of atmospheric extension (i.e.)B/A=3 and 10 (whereB andA are the outer and inner radii of the atmosphere) have been treated.

We find that the partial frequency redistribution gives a larger mean number of scatterings compared to that given by complete redistribution. Velocities tend to reduce the mean number of scatterings and in crease the mean escape probabilities.