Abstract:
In a close binary system, the effects of irradiation
are studied from an extended surface of the secondary component on the atmosphere of the primary. Primary and the
secondary components are assumed to have equal radii and
the thickness of the atmosphere is assumed to be twice that
of the stellar radius of the primary component. Self radiation of the primary component (Ss) is calculated through a
numerical solution of line transfer equation in the comoving frame with Compton broadening due to electron scattering. The solution is developed through discrete space theory
to deal with different velocities in a spherically expanding
medium. The irradiation from the secondary (SI ) is calculated using one dimensional rod model. It is assumed to be
one, five and ten times the self radiation. The total source
function (S = Ss + SI) is the sum of the source functions
due to self radiation and that due to irradiation. The line
fluxes are computed along the line of sight by using the
above source functions. Line profiles are also computed for
different line center optical depths along the line of sight of
the observer at infinity.
We noticed that the source functions against the optical
depth show order of magnitude difference in the medium
with and without reflection and also with the proximity of
the secondary component. It is also noticed that the expansion of the medium produces P Cygni type profiles and the
irradiation enhances the emission in the lines.
