Hydrodynamical calculations in two and three spatial dimensions are necessary in a broad range of astrophysical contexts. With modern parallel supercomputers, they are also becoming more realistic, in that they can be run at modest to high resolution. Performing full radiation hydrodynamical calculations is presently still too computationally expensive. Recently, Hubeny & Burrows (2006) have presented a mixed frame method of solving the time-dependent radiative transfer problem in 2D, but their work is tailored toward neutrino transport where the absence of rapidly changing opacity such as a spectral line makes their approximations appropriate. Similar work has been presented by Mihalas & Klein (1982), Lowrie et al. (1999), and Lowrie & Morel (2001). Taking a different approach Krumholz et al. (2006) derive the flux-limiter to for use in radiation hydrodynamics calculations. Similar work was presented by Cooperstein & Baron (1992). Even though these recent first steps are improvements, they suffer from a loss of accuracy, either in dealing with spectral lines, or in obtaining the correct angular dependence of the photon distribution function or the specific intensity. While these recent works are expedient, they are crude enough that the results of the hydrodynamical calculations cannot be compared directly with observed spectra. Given the fact that computational resources are finite, a final post-processing step is necessary to compare the results of hydrodynamical calculations to observations.
In Hauschildt & Baron (2006, hereafter: Paper I) we described a framework for the solution of the radiative transfer equation for scattering continua in 3D (when we say 3D we mean three spatial dimensions, plus three momentum dimensions) for the time independent, static case. Here we extend our method to include transfer in lines including the case that the line is scattering dominated. Fabiani Bendicho et al. (1997) presented a multi-level, multi-grid, multi-dimensional radiative transfer scheme, using a lower triangular ALO and solving the scattering problem via a Gauss-Seidel method. van Noort (2002) presented a method of solving the full NLTE radiative transfer problem using the short characteristics method in 2-D for Cartesian, spherical, and cylindrical geometry. They also used the technique of accelerated lambda iteration (ALI) (Olson & Kunasz, 1987; Olson et al., 1987), however they restricted themselves to the case of a diagonal accelerated lambda operator (ALO).
We describe our method, its rate of convergence, and present comparisons to our well-tested 1-D calculations.