Spectral Line Shapes in Dense Stellar Plasmas

Spectral line shapes describe the distribution of opacity from bound electronic transitions. Accurate line shape theory is therefore a necessary input for modeling photon transport through the wide range of plasma environments found in stars. Stark broadening, where charged particles perturb the electronic structure of radiating atoms, is often the dominant broadening mechanism in stars, including many stellar photospheres that can be directly observed, and stellar interiors like that of our own sun. Observations of white dwarf star photospheres and helioseismic oscillations, as well as high-energy-density laboratory opacity experiments conducted at the Sandia Z-Machine and the Lawrence Livermore National Ignition Facility, have recently suggested that serious discrepancies persist between modern Stark-broadened line shape models and reality. In this talk, I discuss my work to improve Stark broadening theory in similar dense stellar plasmas by exploring novel techniques for incorporating detailed electronic structure into line shape calculations.