Fe XVII Opacity at Solar Interior Conditions

A recent study of Fe XVII. R-matrix calculations aimed at resolving outstanding opacity problems claimed that substantial photon absorption from atomic core ionization processes was not previously considered. It is shown, however, that major opacity models already include cross-sections that are equivalent to the enhancements reported by the R-matrix method. Furthermore, the R-matrix calculations neglected important cross-sections that help to explain why the resultant opacity is lower than other models in the spectral range measured in transmission experiments relevant to the solar interior.