NOAO >   Observing Info >   Approved Programs >   2010B-0183

Small NOAO Logo

Proposal Information for 2010B-0183


PI: Carlos Abia, Universidad de Granada, cabia@ugr.es
Address: Fisica Teorica y del Cosmos, Avda. Fuentenueva s/n, Granada, Granada E-18071, Spain

CoI: Katia Cunha, NOAO
CoI: Verne V. Smith, NOAO

Title: The origin of fluorine: The first determination of fluorine abundances in extragalactic AGB carbon stars

Abstract: Only for AGB stars does there exist observational evidence that nucleosynthesis of fluorine, as ^19F, is an ongoing process. However, we have recently derived F abundances in Galactic AGB carbon- stars and found much lower F enhancements than previously reported in the literature. This downward revision to the F abundances in Galactic stars results from much improved molecular data and model atmospheres adopted in our recent analyses. The lower F enhancements found places doubt on the real contribution of AGB stars to the chemical evolution of this element. Nevertheless, theoretical AGB models predict large primary F production at low metallicity, but this has not yet been tested observationally. Therefore, \bf we propose to measure F abundances in extragalactic AGB C-stars covering a range in metallicity and belonging to nearby (metal-poor) galaxies. This will lead to the first derivation of F abundances in extragalactic AGB C-stars, to new constraints on nucleosynthetic models and to a better estimation of the contribution of AGB stars to the F inventory in stellar populations.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2010B-0183

noaoprop-help@noao.edu

Small NOAO Logo