RADIATIVE-TRANSFER IN AXISYMMETRICAL CIRCUMSTELLAR DUST SHELLS

A non-spherical dust shell radiative simulation, aiming both at analys ing the existing data on evolved stars and at preparing the interpreta tion of the scheduled high angular resolution imaging, is described. T he calculated radiative equilibrium derives from a Monte Carlo method. The exact solution of the transfer is thus computed for different wav elengths. Results are obtained for different modellings with peculiar axisymmetric dust density distributions. The broad band spectra, the b rightness distribution of the shell as a fonction of wavelength and vi ew angle and the corresponding visibility maps, display typical observ able properties. In a first attempt the spectrum and the visible image of the Red Rectangle are reproduced with a flared disc.