On the completeness of the analysis of third and fourth spectra of the iron group, and the spectra of early B stars

Abstract

The spectroscopic analysis of normal, early B stars requires a sound atomic data base, especially for the third and fourth spectra of the iron-group elements. We review the present status of the term analyses of third and fourth spectra of vanadium-nickel as of the Sugar-Corliss compilation. Incompleteness of the analyses of the third spectra is typically evident about halfway to the first ionization limit. The fourth spectra are less well known. For Fe, Co, and Ni IV, only the lowest three configurations have been located. Copernicus spectra described by Rogerson and his coworkers have been studied in detail. We conclude that present atomic data is approaching a sufficient degree of completeness to allow a realistic analysis of the satellite ultraviolet of the “normal” star. Without analytical work of the last decade, the analysis of the UV spectrum of this star would have been hopeless.