论文标题
凸出球状簇ESO〜456-SC38的光谱分析
Spectroscopic analysis of the bulge Globular Cluster ESO~456-SC38
论文作者
论文摘要
有人提出，银河系中最古老的恒星种群紧密地绑定并局限于银河系的中央地区。这就是为什么位于凸起区域的少数球状簇被认为是银河系原始地层阶段的残余的原因之一。球状簇，ESO 456-SC38（Djorgovski〜2）就是这样的簇。它有一个蓝色的水平分支，预计非常靠近银河系中心，并有一个将其限制在凸起/条形区域的轨道。使用Apogee DR16提出了这个重变红色群集中七颗恒星的第一批α恒星。 N，C，Na和Al的丰度显着扩散，表明该群集中存在多个恒星种群。使用Brava-RR的Gaia Dr2适当的运动和径向速度，我们确认RR Lyrae恒星属于该球状簇。
It has been suggested that the oldest stellar populations in the Milky Way Galaxy are tightly bound and confined to the central regions of the Galaxy. This is one of the reasons why a handful of globular clusters located in the bulge region are thought to be remnants of the primeval formation stages of the Milky Way. The globular cluster, ESO 456-SC38 (Djorgovski~2) is one such cluster; it has a blue horizontal branch, is projected very close to the center of the Galaxy, and has an orbit confining it to the bulge/bar region. The first alpha abundances of seven stars in this heavily reddened cluster are presented using APOGEE DR16. A significant spread in the abundances of N, C, Na, and Al indicates the presence of multiple stellar populations in this cluster. Using Gaia DR2 proper motions and radial velocities from BRAVA-RR, we confirm RR Lyrae stars belong to this globular cluster.
