Radiative transfer in an LTE atmosphere: An integral kernel formulation of the Compton scatter source term

The purpose of this paper is the computation of the spectrum of the radiation scattered by an LTE atmosphere irradiated by a given spectrum. The expression given for the integral kernel of Compton scatter takes into account both the Doppler shift and the Compton frequency shift. Collective (plasma) phenomena are neglected, and we use throughout the binary encounter approximation. Our result is accurate to terms of 2nd order in v/c (v being the electron velocity, c the light velocity). A comparison is made with some previous results (,^{(1) (2)}).