论文标题
盖亚（Gaia）在盖亚（Gaia
A GALAH View of the Chemical Homogeneity and Ages of Stellar Strings Identified in Gaia
论文作者
论文摘要
盖亚（Gaia）的出现导致发现了近300个延长的恒星协会（称为“弦”），跨越了数百个parsecs，宽度仅为parsecs。这些新发现的人群是研究银河系薄磁盘的组装过程的绝佳实验室。在这项工作中，我们使用Galah DR3的数据来研究18个新发现恒星种群的化学分布和年龄，其中10个是字符串，其中8个在形态学上是紧凑的。我们估计每个人群[x/h]中的内在丰度分散体，并将其与当地领域和开放群集M 67进行比较。我们发现，除这些群体中的所有群体都比本地领域更具化学性。此外，一半的字符串，即Theias 139、169、216、303和309具有固有的[X/H]分散体，在大多数元素中介于0.01至0.07 DEX之间，等效于许多开放群集。这些结果为恒星形成和局部星际培养基（ISM）的化学均匀性提供了重要的新观察约束。我们研究了每个人群的LI和化学时钟丰度（例如[SC/BA]，[CA/BA]，[Ti/Ba]和[mg/Y]），发现化学建议的年龄通常支持除六个结构以外的所有等级年龄。这项工作强调了化学在运动学相关恒星群体研究中具有的独特优势。
The advent of Gaia has led to the discovery of nearly 300 elongated stellar associations (called `strings') spanning hundreds of parsecs in length and mere tens of parsecs in width. These newfound populations present an excellent laboratory for studying the assembly process of the Milky Way thin disk. In this work, we use data from GALAH DR3 to investigate the chemical distributions and ages of 18 newfound stellar populations, 10 of which are strings and 8 of which are compact in morphology. We estimate the intrinsic abundance dispersions in [X/H] of each population and compare them with those of both their local fields and the open cluster M 67. We find that all but one of these groups are more chemically homogeneous than their local fields. Furthermore, half of the strings, namely Theias 139, 169, 216, 303, and 309, have intrinsic [X/H] dispersions that range between 0.01 and 0.07 dex in most elements, equivalent to those of many open clusters. These results provide important new observational constraints on star formation and the chemical homogeneity of the local interstellar medium (ISM). We investigate each population's Li and chemical clock abundances (e.g., [Sc/Ba], [Ca/Ba], [Ti/Ba], and [Mg/Y]) and find that the ages suggested by chemistry generally support the isochronal ages in all but six structures. This work highlights the unique advantages that chemistry holds in the study of kinematically-related stellar groups.
