Polarized Line Formation with J-state Interference in the Presence of Magnetic Fields. I. Partial Frequency Redistribution in the Collisionless Regime

Abstract

Quantum interference phenomena play a fundamental role in astrophysical spectra that are formed by coherent scattering processes. Here we derive a partial frequency redistribution (PRD) matrix that includes J-state interference in the presence of magnetic fields of arbitrary strength. The paper focuses on PRD in the collisionless regime, which in the traditional PRD terminology is referred to as Hummer's type-II scattering. By limiting the treatment to the linear Zeeman regime, for which the Zeeman splitting is much smaller than the fine-structure splitting, it is possible to formulate analytical expressions for the PRD matrices. In the special case of non-magnetic scattering we recover the redistribution matrix derived from an independent quantum electrodynamic formulation based on the metalevel theory.