THE FIRST FLUORINE ABUNDANCE DETERMINATIONS IN EXTRAGALACTIC ASYMPTOTIC GIANT BRANCH CARBON STARS

Journal Article · Wed Aug 10 04:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/737/1/L8· OSTI ID:21562492

Abia, C; Cristallo, S; Dominguez, I ^[1]; Cunha, K; Smith, V V ^[2]; De Laverny, P; Recio-Blanco, A ^[3]; Straniero, O ^[4]

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1. Dpto. Fisica Teorica y del Cosmos, Universidad de Granada, 18071 Granada (Spain)
2. National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States)
3. University of Nice-Sophia Antipolis, CNRS (UMR 6202), Cassiopee, Observatoire de la Cote d'Azur, B.P. 4229, 06304 Nice Cedex 4 (France)
4. INAF-Osservatorio di Collurania, 64100 Teramo (Italy)

Fluorine ({sup 19}F) abundances (or upper limits) are derived in six extragalactic asymptotic giant branch (AGB) carbon stars from the HF(1-0) R9 line at 2.3358 {mu}m in high-resolution spectra. The stars belong to the Local Group galaxies, Large Magellanic Cloud, Small Magellanic Cloud, and Carina dwarf spheroidal, spanning more than a factor of 50 in metallicity. This is the first study to probe the behavior of F with metallicity in intrinsic extragalactic C-rich AGB stars. Fluorine could be measured only in four of the target stars, showing a wide range in F enhancements. Our F abundance measurements together with those recently derived in Galactic AGB carbon stars show a correlation with the observed carbon and s-element enhancements. The observed correlations, however, display a different dependence on the stellar metallicity with respect to theoretical predictions in low-mass, low-metallicity AGB models. We briefly discuss the possible reasons for this discrepancy. If our findings are confirmed in a larger number of metal-poor AGBs, the issue of F production in AGB stars will need to be revisited.

• OSTI ID: 21562492
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 737; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
CARBON STARS
ELEMENT ABUNDANCE
ELEMENTS
FLUORINE
FLUORINE 19
FLUORINE ISOTOPES
GALAXIES
HALOGENS
ISOTOPES
LIGHT NUCLEI
MAGELLANIC CLOUDS
MAIN SEQUENCE STARS
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
STABLE ISOTOPES
STARS