SIMBAD references

2007ApJ...667L..81S - Astrophys. J., 667, L81-L84 (2007/September-3)

Fluorine in a carbon-enhanced metal-poor star.


Abstract (from CDS):

The fluorine abundance of the carbon-enhanced metal-poor (CEMP) star HE 1305+0132 has been derived by analysis of the molecular HF (1-0) R9 line at 2.3357 µm in a high-resolution (R=50,000) spectrum obtained with the Phoenix spectrometer and Gemini-South telescope. Our abundance analysis makes use of a CNO-enhanced ATLAS12 model atmosphere characterized by a metallicity and CNO enhancements determined utilizing medium-resolution (R=3000) optical and near-IR spectra. The effective iron abundance is found to be [Fe/H]=-2.5, making HE 1305+0132 the most Fe-deficient star, by more than an order of magnitude, for which the abundance of fluorine has been measured. Using spectral synthesis, we derive a supersolar fluorine abundance of A(19F)=4.96±0.21, corresponding to a relative abundance of [F/Fe]=+2.90. A single line of the Phillips C2 system is identified in our Phoenix spectrum, and along with multiple lines of the first-overtone vibration-rotation CO (3-1) band head, C and O abundances of A(12C)=8.57±0.11 and A(16O)=7.04±0.14 are derived. We consider the striking fluorine overabundance in the framework of the nucleosynthetic processes thought to be responsible for the C-enhancement of CEMP stars and conclude that the atmosphere of HE 1305+0132 was polluted via mass transfer by a primary companion during its asymptotic giant branch phase. This is the first study of fluorine in a CEMP star, and it demonstrates that this rare nuclide can be a key diagnostic of nucleosynthetic processes in the early Galaxy.

Abstract Copyright:

Journal keyword(s): Stars: Abundances - Stars: Atmospheres - Stars: Carbon - stars: individual (HE 1305+0132) - Stars: Population II

Simbad objects: 1

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2007ApJ...667L..81S and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact