论文标题

Lamost遇到Gaia:银河开放式簇

LAMOST meets Gaia: The Galactic Open Clusters

论文作者

Fu, Xiaoting, Bragaglia, Angela, Liu, Chao, Zhang, Huawei, Xu, Yan, Wang, Ke, Zhang, Zhi-Yu, Zhong, Jing, Chang, Jiang, Li, Lu, Chen, Li, Chen, Yang, Wang, Fei, Gjergo, Eda, Wang, Chun, Yue, Nannan, Zhang, Xi

论文摘要

开放式簇是沿银河系平面诞生和进化的,上面印有银河盘的历史,包括化学和动力学进化。开放簇的化学和动力学特性可以源自其成员恒星的光度,光谱和天体数据。基于盖亚任务的光度和天文数据,在文献中已经确定了2000多个银河系簇中的恒星的成员。然而,化学和运动学特性仍然以许多这些簇而闻名。与较大的光谱调查Lamost(数据发行8)和Gaia(数据释放2)协同作用,我们报告了386个开放式群集的新综合目录。该目录对径向速度,金属性和动力学性质(例如轨道,偏心率,角动量,总能量,总能量和3D银河速度)具有均匀的参数确定。这些参数允许第一个径向速度确定和第一个光谱[Fe/H]分别针对44和137个簇进行测定。多数簇的金属性分布显示出半半径的参数空间,总能量和角动量的Z分量的趋势下降 - 除了两个在其自身参数平面上显示平坦尾巴的旧组。年龄较大和年龄较大的500 MYR的簇种群在光盘上分布多样。后者与银河盘耀斑具有空间一致性。非常年轻的簇(<100 MYR)和附近的分子云之间的3-D空间比较显示沿Radcliffe气体云波沿着多种金属性分布,表明可能沿波浪沿波浪形成不均匀的混合或快速的恒星形成。该目录将作为追踪银河系的化学和动力发展的有用工具。

Open Clusters are born and evolve along the Milky Way plane, on them is imprinted the history of the Galactic disc, including the chemical and dynamical evolution. Chemical and dynamical properties of open clusters can be derived from photometric, spectroscopic, and astrometric data of their member stars. Based on the photometric and astrometric data from the Gaia mission, the membership of stars in more than 2000 Galactic clusters has been identified in the literature. The chemical and kinematical properties, however, are still poorly known for many of these clusters. In synergy with the large spectroscopic survey LAMOST (data release 8) and Gaia (data release 2), we report a new comprehensive catalogue of 386 open clusters. This catalogue has homogeneous parameter determinations of radial velocity, metallicity, and dynamical properties, such as orbit, eccentricity, angular momenta, total energy, and 3D Galactic velocity. These parameters allow the first radial velocity determination and the first spectroscopic [Fe/H] determination for 44 and 137 clusters, respectively. The metallicity distribution of majority clusters shows falling trends in the parameter space of the Galactocentric radius, the total energy, and the Z component of angular momentum -- except for two old groups that show flat tails in their own parameter planes. Cluster populations of ages younger and older than 500 Myrs distribute diversely on the disc. The latter has a spatial consistency with the Galactic disc flare. The 3-D spatial comparison between very young clusters (< 100 Myr) and nearby molecular clouds revealed a wide range of metallicity distribution along the Radcliffe gas cloud wave, indicating a possible inhomogeneous mixing or fast star formation along the wave. This catalogue would serve the community as a useful tool to trace the chemical and dynamical evolution of the Milky Way.

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