Oxygen line formation in 3D hydrodynamical model atmospheres
Abstract
Description
The formation of [O I], O I and OH lines in metal-poor stars has been studied by means of 3D hydrodynamical model atmospheres. For O I detailed 3D non-LTE calculations have been performed. While the influence of 3D model atmospheres is minor for [O I] and O I lines, the very low temperatures encountered at low metallicities have a drastic impact on the OH lines. As a result, the derived O abundances are found to be systematically overestimated in 1D analyses, casting doubts on the recent claims for a monotonic increase in [O/Fe] towards lower metallicities.
Invited talk presented at IAU General Assembly Joint Discussion 8 "Oxygen abundances in old stars and implications for nucleosynthesis and cosmology", Manchester, August 2000. The full version of the talk can be found at http://www.astro.uu.se/~martin/talks/Manchester00
Invited talk presented at IAU General Assembly Joint Discussion 8 "Oxygen abundances in old stars and implications for nucleosynthesis and cosmology", Manchester, August 2000. The full version of the talk can be found at http://www.astro.uu.se/~martin/talks/Manchester00