A simple approximation forJ v (σ v ,κ v ,τ v,B v ), and its application for temperature-correction procedures

For the case of isotropic coherent scattering plus absorption a simple expression is given (Equation 12) to compute the mean intensity of the radiationJ_v (as a function of optical depth _v) if the scattering coefficient _v, the absorption coefficientK_v and the Planck functionB_v are given as a function of depth. In general the accuracy of this approximation is of the order of a few percent.A fairly simple temperature-correction procedure for the case when scattering is important is described.