3-D Monte Carlo radiative transfer calculation of resonance line   formation in the inhomogeneous expanding stellar wind
  We study the effects of optically thick clumps, non-void inter-clump medium, variation of the onset of clumping, and velocity dispersion inside clumps on the formation of resonance lines. For this purpose we developed a full 3-D Monte Carlo Radiative Transfer (MCRT) code that is able to handle 3-D shapes of clumps and arbitrary 3-D velocity fields. The method we developed allows us to take into account contributions from density and velocity wind inhomogeneities to the total opacity very precisely. The first comparison with observation shows that 3-D density and velocity wind inhomogeneities have a very strong influence on the resonance line formation, and that they have to be accounted for in order to obtain reliable mass-loss rate determinations. 
Brankica \v{S}urlan, Wolf-Rainer Hamann, Ji\v{r}\'i Kub\'at, Lidia   Oskinova, Achim Feldmeier
astro-ph.SR