Fluorine abundances in galactic asymptotic giant branch stars

• An analysis of the fluorine abundance in Galactic asymptotic giant branch (AGB) carbon stars (24 N-type, 5 SC-type, and 5 J-type) is presented. This study uses the state-of-the-art carbon-rich atmosphere models and improved atomic and molecular line lists in the 2.3 mu m region. Significantly lower F abundances are obtained in comparison to previous studies in the literature. This difference is mainly due to molecular blends. In the case of carbon stars of SC-type, differences in the model atmospheres are also relevant. The new F enhancements are now in agreement with the most recent theoretical nucleosynthesis models in low-mass AGB stars, solving the long-standing problem of F in Galactic AGB stars. Nevertheless, some SC-type carbon stars still show larger F abundances than predicted by stellar models. The possibility that these stars are of larger mass is briefly discussed.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

nuclear reactions

nucleosynthesis

abundances

stars: abundances

stars: AGB and post-AGB

stars: carbon

Physics

Fysik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)