Polarization of resonance lines formed in extended spherical atmospheres

Abstract

The present consideration of the polarization problem posed by resonance lines in extended spherical atmospheres assumes that the atmosphere in question is at rest and emphasizes the determination of constraints that can be placed on model parameters for observations of polarization across resonance lines. A comparison is conducted of polarized lines formed under three kinds of line-scattering, namely those which are coherent, completely redistributing, and partial-frequency redistributing. Polarization's dependence on opacity laws, extendedness, and optical depth is treated in detail, as is the distribution of line intensity and polarization across the visible disk of an extended model stellar atmosphere