On the modified random walk algorithm for Monte-Carlo radiation transfer

摘要

Min etal. (2009) presented two complementary techniques thatuse the diffusion approximation to allow efficient Monte-Carloradiation transfer in very optically thick regions: a modified randomwalk and a partial diffusion approximation. In this note, I show thatthe calculations required for the modified random walk method can besignificantly simplified. In particular, the diffusion coefficient andthe mass absorption coefficients required for the modified random walkare in fact the same as the standard diffusion coefficient and thePlanck mean mass absorption coefficient.Key words: radiative transfer - diffusion - circumstellar matter - methods: numerical