论文标题
$ {}^{6} {\ rm li} $在halo星星中的非观察的含义
Implications of the Non-Observation of ${}^{6}{\rm Li}$ in Halo Stars for the Primordial ${}^{7}{\rm Li}$ Problem
论文作者
论文摘要
原始锂问题与假设$ {}^{7} {\ rm li} $密切相关。有两个关键的证据表明，这些恒星并未显着耗尽其最初的$ {}^{7} {7} {\ rm li} $：i）在低金属性下测得的li丰度缺乏分散体； ii）检测至少两个光晕星中更脆弱的$ {}^{6} {\ rm li} $同位素。所谓的$ {}^{6} {\ rm li} $检测与宇宙 - 射线核合成的预测非常吻合，该核素核合成的预测负责$ {}^{6} {\ rm li} $。这种一致性留下了$ {}^{6} {\ rm li} $ deptetion的耗尽的空间，并暗示更坚固的$ {}^{7} {\ rm li} $在很大程度上逃避了毁灭性。最近的（re） - 光晕星的观察质疑$ {}^{7} {\ rm li} $ depletion：i）锂丰度现在显示出明显的分散，ii）敏感$ {}^{6} {6} {\ rm li} $ search {\ rm li} $ search in of $ rm li} $ search offer coble of clign clign clign coint of clign clign to clight of clink files of use of $^}} li}/{}^{7} {\ rm li} $比率。紧密的新$ {}^{6} {\ rm li} $上限通常远低于宇宙射线核合成的预测，这意味着大量的$ {}^{6} {\ rm li} $ li} $ 50。因此，在$ {}^{6} {\ rm li} $ depletion上的下限是$ {}^{7} {\ rm li} $ depletion的相等数量，足以解决PrimorDial $ {}^}^{7} {7} {\ rm li} $问题。这张图片与$ {}^{7} {\ rm li} $的出色模型一致，而不是$ {}^{6} {\ rm li} $耗尽的耗尽，并增强了锂问题具有天体物理解决方案的情况。我们通过建议未来可以测试这些想法的观察结果来结束。 （简略）
The primordial Lithium Problem is intimately connected to the assumption that ${}^{7}{\rm Li}$ observed in metal-poor halo stars retains its primordial abundance, which lies significantly below the predictions of standard big-bang nucleosynthesis. Two key lines of evidence have argued that these stars have not significantly depleted their initial ${}^{7}{\rm Li}$: i) the lack of dispersion in Li abundances measured at low metallicity; and ii) the detection of the more fragile ${}^{6}{\rm Li}$ isotope in at least two halo stars. The purported ${}^{6}{\rm Li}$ detections were in good agreement with predictions from cosmic-ray nucleosynthesis which is responsible for the origin of ${}^{6}{\rm Li}$. This concordance left little room for depletion of ${}^{6}{\rm Li}$ depletion, and implied that the more robust ${}^{7}{\rm Li}$ largely evaded destruction. Recent (re)-observations of halo stars challenge the evidence against ${}^{7}{\rm Li}$ depletion: i) lithium abundances now show significant dispersion, and ii) sensitive ${}^{6}{\rm Li}$ searches now reveal only firm upper limits to the ${}^{6}{\rm Li}/{}^{7}{\rm Li}$ ratio. The tight new ${}^{6}{\rm Li}$ upper limits generally fall far below the predictions of cosmic-ray nucleosynthesis, implying that substantial ${}^{6}{\rm Li}$ depletion has occurred--by factors up to 50. We show that in stars with ${}^{6}{\rm Li}$ limits and thus lower bounds on ${}^{6}{\rm Li}$ depletion, an equal amount of ${}^{7}{\rm Li}$ depletion is more than sufficient to resolve the primordial ${}^{7}{\rm Li}$ Problem. This picture is consistent with stellar models in which ${}^{7}{\rm Li}$ is less depleted than ${}^{6}{\rm Li}$, and strengthen the case that the Lithium Problem has an astrophysical solution. We conclude by suggesting future observations that could test these ideas. (abridged)
