Theoretical study of irradiation effects in close binaries

Abstract

The effect of irradiation is studied in a close binary system assuming that the secondary component is a point source, moving in a circular orbit. The irradiation effects are calculated on the atmosphere of the primary component in a 3-dimensional Cartesian coordinate geometry. In treating the reflection effect theoretically, the total radiation (S_{T}) is obtained as the sum of the radiation of 1) the effect of irradiation on the primary component which is calculated by using one dimensional rod model (S_{r}) and 2) the self radiation of the primary component which is calculated by using the solution of radiative transfer equation in spherical symmetry (S_{s}). The radiation field is estimated along the line of sight of the observer at infinity. It is shown how the radiation field changes depending on the position of the secondary component.