Optical depth effects on the formation of spectral lines in rotating and expanding spherical atmospheres

Abstract

The effect of high optical depths and large rotational velocities on the spectral lines in rotating and radial expanding spherical shells is investigated. It is assumed that the outer radius of the shell is three times the inner radius and that there are no velocity gradients in the shell; the radial optical depths are 10, 50, 100, and 500. The shell rotates with velocities varying as 1/p, where p is the perpendicular distance from the axis of rotation. Two expansion (radial) velocities, V = 0 and V = 10 mean thermal units, are considered, with maximum rotational velocities of 0, 5, 10, and 20. In the shell with no radial motions, symmetric lines with emission in the wings were obtained for rotational velocities = 0 and 5, while for rotational velocities greater than or equal to 10, symmetric absorption lines were formed. Lines with central emission were obtained in the case of an expanding shell