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J. Melendez (Caltech)
We have determined Li abundances in unevolved halo stars (-3.4 < [Fe/H] < -1) employing an improved temperature scale based on the Infrared Flux Method. Previous studies of low metallicity stars have found a low Li primordial abundance of A(Li) = 2.1, but constraints imposed by WMAP cosmic background observations suggest A(Li) = 2.6. We have obtained a higher Li abundance of A(Li) = 2.4, alleviating the conflict between WMAP and previous Li abundance determinations. Nevertheless, there is still a 0.2 dex discrepancy, which, considering systematic errors, could be as high as 0.3 dex (a factor of 2) between the Li Spite plateau and the prediction from Big Bang primordial nucleosynthesis. This work was partially supported by NSF grant AST-0205951.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.