Oxygen Abundances Derived from UV OH and O I IR Lines in Very Metal-Poor Stars

Oxygen abundances in metal - poor subgiants as determined from [ O i ] , O i and OH lines ⋆

Oxygen abundances in unevolved metal-poor stars from near-UV OH lines

We have performed a detailed oxygen abundance analysis of 23 metal-poor (−3.0<[Fe/H]< −0.3) unevolved halo stars and one giant through the OH bands in the near UV, using high-resolution echelle spectra. Oxygen is found to be overabundant with respect to iron in these stars, with the [O/Fe] ratio increasing from 0.6 to 1 between [Fe/H]=−1.5 and −3.0. The behavior of the oxygen overabundance with...

OXYGEN ABUNDANCES IN METAL-POOR STARS (−2.2 < [Fe/H] < −1.2) FROM INFRARED OH LINES

Infrared OH lines at 1.55 1.56 μm in the H-band were obtained with the Phoenix high-resolution spectrograph at the 2.1m telescope of the Kitt Peak National Observatory for a sample of 14 metal-poor stars. Detailed analyses of the sample stars have been carried out, deriving stellar parameters based on two methods: (a) spectroscopic parameters; (b) IRFM effective temperatures, trigonometric grav...

KECK-NIRSPEC INFRARED OH LINES: OXYGEN ABUNDANCES IN METAL-POOR STARS DOWN TO [Fe/H]

Infrared OH lines at 1.5 1.7 μm in the H band were obtained with the NIRSPEC highresolution spectrograph at the 10m Keck Telescope for a sample of seven metal-poor stars. Detailed analyses have been carried out, based on optical high-resolution data obtained with the FEROS spectrograph at ESO. Stellar parameters were derived by adopting infrared flux method effective temperatures, trigonometric...

Abundances in Very Metal-Poor Stars

Metal-poor stars provide information on the characteristics and chemical evolution of the halo population of the Galaxy, the first epoch of star formation and Galaxy formation (not just locally but with relevance to high-redshift objects), and big bang nucleosynthesis. This review looks at recent developments in this subject.