arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1301.0163astro-ph.SRastro-ph.GA
收藏

斯隆数字巡天中的富锂场巨人

Lithium-Rich Field Giants in the Sloan Digital Sky Survey

Sarah L. Martell, Matthew D. Shetrone

摘要:

我们提出了一个搜索后主序星在银河系中的锂丰度巨大。使用斯隆数字巡天的中分辨率光谱,以及来自Hobby-Eberly望远镜的高分辨率后续光谱,我们确定了23颗log λ(Li)大于1.95的关闭后恒星,其中14颗log λ(Li)> 2.3,8颗log λ(Li)> 3.0,远高于演化恒星预期的低水平。与理论等时线的比较表明,我们的一些富锂恒星隶属于上红巨星分支,渐近巨星分支和红团,而不是RGB凸点,这是一个挑战,现有的模型的锂生产在演化的恒星。

英文摘要:

We present a search for post-main-sequence field stars in the Galaxy with atypically large lithium abundances. Using moderate-resolution spectra taken as part of the Sloan Digital Sky Survey, along with high-resolution followup spectroscopy from the Hobby-Eberly Telescope, we identify 23 post-turnoff stars with log epsilon(Li) greater than 1.95, including 14 with log epsilon(Li) > 2.3 and 8 with log epsilon(Li) > 3.0, well above the low level expected for evolved stars. Comparison with theoretical isochrones indicates that some of our Li-rich stars are affiliated with the upper red giant branch, the asymptotic giant branch and the red clump rather than the RGB bump, which is a challenge to existing models of Li production in evolved stars.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑