3D Continuum Radiative Transfer: An adaptive grid construction algorithm based on the Monte Carlo method.

The continuum radiative transfer is a common problem in astrophysics that must be solved to describe the physics and interpret observations of objects embedded for instance in a dusty medium. The high angular resolution of present ground-based and space instruments reveal or are expected to reveal complex structures and geometries in astrophysical objects. It is thus necessary to take into account the three spatial dimensions. We chose the Monte Carlo (MC) method to solve the continuum radiative transfer problem. We use a natural by-product of the MC method, the locations of the photon interaction with the medium, to build an adaptive temperature grid. I will present the new algorithm used for the construction of the grid and the radiative transfer code developed on it. I will illustrate the capabilities of this code with possible astrophysical applications (clumps around an AGB star, warps in an accretion disc).