Iron-group opacities for B stars

Frequency-dependent photon absorption and scattering transport cross-sections for iron-group elements were generated using a revised version of the opal opacity code. The calculations take advantage of advances in computers to generate improved atomic data as well as several fast algorithms developed for the computational demanding bound–bound spectrum. The new iron group calculations are combined with the existing opal data for lighter elements to generate astrophysical opacities at matter conditions applicable to B stars. The results are slightly reduced Rosseland mean opacities of Population I stars at the peak of the Z-bump. The analysis explores several uncertainties related to the iron group opacities and includes comparisons with existing opal and OP results.