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FLUORINE IN A CARBON-ENHANCED METAL-POOR STAR
| Content Provider | Semantic Scholar |
|---|---|
| Author | Schuler, Simon C. Cunha, Kátia S. Smith, Verne V. Sivarani, T. S. Beers, Timothy C. Lee, Young S. |
| Copyright Year | 2008 |
| Abstract | 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 = 3, 000) 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 super-solar fluorine abundance of A(F) = 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(C) = 8.57 ± 0.11 and A(O) = 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. Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile; sschuler@ctio.noao.edu |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://arxiv.org/pdf/0707.4252v1.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | BLOC1S4 gene Carbon Monoxide Poisoning Dietary Iron Field electron emission Fluorine GUCY2C protein, human Image resolution Mental Processes Stars, Celestial |
| Content Type | Text |
| Resource Type | Article |
