Physically motivated non-uniform photospheric flux distributions

Construct physically motivated non-uniform radiative-flux distributions over aspherical photospheres by specifying an internal-energy distribution, and incorporate them into polarization calculations to obtain more realistic predictions than those based on uniform surface flux.

Background

The polarization calculations assume that the radiative flux is uniform over the photosphere. The paper notes that this approximation becomes increasingly inaccurate for strongly aspherical geometries because, under diffusion, radiation preferentially propagates along directions in which the internal-energy or temperature gradient is steepest. In highly prolate spheroids with centrally located heating, for example, radiation may diffuse preferentially toward equatorial regions, altering their contribution to the net polarization.

A more realistic treatment therefore requires a physical model for the internal-energy distribution and the resulting surface-flux variation. The paper explicitly defers such a calculation to future work.