论文标题
银河系的多个人群中的不同钠的增强。
Different Sodium enhancements among multiple populations of Milky Way globular clusters
论文作者
论文摘要
我们搜索了小径，以了解古代银河系群的第一代和第二代恒星中测得的不同的含量。为此，我们从最近的文献中收集了上述Na的丰度，轨道参数，结构和内部动力学性质以及年龄，并以28个球状簇的均匀量表。我们发现，通过第一代恒星和第二代恒星之间的Na丰度的差异测量的群群内富集表现出趋势与第一代恒星的Na丰度的函数，从某种意义上说，第一代恒星越贫穷，Na富集就越大。通过使用球状簇轨道的倾斜度，分析的Na富集还暗示了一个〜0.3 Dex的边界以区分具有较大Na富集的增生的球状簇的球状簇具有积聚或原位的起源。由于在积聚的球状簇中可以看到相对较大的群内Na增强功能，并且在原位形成的球状簇中观察到较小的Na增强功能（尽管不是仅限于），因此我们推测有可能将Na富集的振幅与构件范围链接相关。在第一代和第二代恒星形成时，球状簇似乎可以保留对这个等级星系形成过程的记忆。
We searched for trails to understand the different Na abundances measured in first and second generation stars of ancient Milky Way globular clusters. For that purpose, we gathered from the recent literature the aforementioned Na abundances, orbital parameters, structural and internal dynamical properties and ages in an homogeneous scale of 28 globular clusters. We found that the intra-cluster Na enrichment, measured by the difference of Na abundances between first and second generation stars, exhibits a trend as a function of the Na abundances of first generation stars, in the sense that the more Na-poor the first generation stars, the larger the Na enrichment. By using the inclinations of the globular clusters' orbits, the analyzed Na enrichments also hinted at a boundary at ~0.3 dex to differentiate globular clusters with an accreted or in situ origin, the accreted globular clusters having larger Na enrichments. Because relatively larger intra-cluster Na enhancements are seen in accreted globular clusters, and small Na enhancements are observed in globular clusters formed in situ (although not exclusively), we speculate with the possibility that the amplitude of the Na enrichment could be linked with the building block paradigm. Globular clusters at the time of formation of first and second generation stars would seem to keep memory of this hierarchical galaxy formation process.
