Improved Radiative Transfer in the ANTARES Code

Abstract

One of the most difficult and time-consuming tasks in multi-dimensional stellar radiative-hydrodynamics simulations is the calculation of the radiation field. We present two major improvements we achieved for the ANTARES code in this context. The first one is the use of Bezier splines in combination with the short characteristic method, resulting in a radiative transfer solver which shows more realistic results (less artifacts) and an increased stability compared to the method used so far. The second improvement presented is a radiative transfer solver based on the Eddington approximation. It allows for fast calculation of the radiation field with only a minor loss of precision. Additionally, it shows good numerical properties. These methods for radiative transfer, as newly-implemented within ANTARES, allow improved numerical results in the case of the Bezier method and much faster calculations in the case of the Eddington approximation.