Maria Fernanda Nieva Universität Erlangen

Accurate Quantitative Spectroscopy of OB Stars (pdf)

A state-of-the-art analysis technique able to simultaneously reproduce the entire H, He and C spectra of OB-type stars in the visual and the near-IR is presented. The spectrum synthesis relies on a hybrid non-LTE approach involving robust model atoms based on precise atomic data. Highly accurate atmospheric parameters free of systematic error are derived for a sample of randomly selected stars in the solar vicinity. A mean carbon abundance of 8.33 +/- 0.03 is indicated. Up to 40 features from C II-IV are considered. This includes the prominent C II 4267 and 6578/82 A lines, suitable for abundance determinations in fast-rotating and extragalactic objects. An excellent starting point for future highly-precise abundance analyses of other metals is established, allowing to put tight constraints on stellar and galactochemical evolution.