Oxygen abundances: new results from [O I] lines

Supersolar oxygen-to-iron ratios are known to exist in nearly all metal-poo r stars. But there is no general agreement on the magnitude of these relati ve overabundances. New high resolution spectra of evolved stars over a larg e metallicity range have been gathered, from which lines of [O I], Sc II, a nd Fe II have been measured. Abundance ratios [O/Sc] and [O/Fe], insensitiv e to most model atmospheric uncertainties, have been derived and correlated with overall metallicity. These ratios both are consistent with earlier st udies of the [O I] lines in metal-poor stars: [O/Sc]similar or equal to [O/ Fe]similar or equal to +0.4, with possibly a small upward trend with decrea sing [Fe/H]. (C) 2001 Elsevier Science BY. All rights reserved.