Energy Balance in Circumstellar Envelopes

Abstract

AbstractWe have successfully determined the kinetic temperature of the electron gas as a function of position in the circumstellar envelopes of Be stars. Our method yields a self-consistent solution of the equation for energy conservation, thus eliminating the necessity to assume arbitrarily a temperature for the gas. Our technique has been applied to Be stars of differing spectral classes, and we have also used several models for the distribution of the circumstellar material. The observed shape and relative line strength of the Hα line for several Be stars were matched successfully with these models. Recently we have begun to investigate the role of the diffuse radiation field in the Lyman continuum using the on-the-spot approximation. As a preliminary step to including metallic line cooling by the circumstellar gas, we have determined iron ionization fractions throughout the disks of both an early-type and a late-type Be star.