RII partial frequency redistribution function and its effects on the formation of lines in expanding spherical atmospheres

Abstract

The redistribution in frequency in lines formed in atmospheres in which the matter is moving radially outwards with velocity gradients is studied in the rest frame of the star. We velocity gradients is studied in the rest frame of the star. We have considered the RII angle averaged function (see Hummer 1962) with radiation damping in the atom’s rest frame and assumed a non LTE two level atom.