论文标题
解开银河系。 ii。 3 kpc以内的结构
Untangling the Galaxy. II. Structure within 3 kpc
论文作者
论文摘要
我们介绍了GAIA DR2数据的层次聚类分析的结果，以搜索集群，共同移动组和其他恒星结构。当前的论文以先前工作的样本为基础，将其从1 kpc扩展到3 kpc，将确定的结构数量增加到8292。为了帮助对种群的分析，我们开发了一种称为Auriga的神经网络，以强遵守年龄，巨大的年龄，巨大的年龄，基于恒星组的距离，并基于投入型帕克拉克萨克斯的距离。我们应用Auriga不仅得出本文中发现的结构的性质，而且先前鉴定出开放群集的属性。通过这项工作，我们检查了螺旋臂的时间结构。具体来说，我们发现射手座的手臂在最后100个MYR中已移动> 500 PC，而Perseus Arm在过去25个MYR中一直在恒星形成活动中遇到相对的平静。我们从上一篇论文中证实了关于螺旋臂的瞬时性质的发现，并有几点过渡的时间范围。最后，我们发现了一个奇特的〜1个回旋式恒星，似乎是中心为中心的。目前尚不清楚它的起源是什么。
We present the results of the hierarchical clustering analysis of the Gaia DR2 data to search for clusters, co-moving groups, and other stellar structures. The current paper builds on the sample from the previous work, extending it in distance from 1 kpc to 3 kpc, increasing the number of identified structures up to 8292. To aid in the analysis of the population properties, we developed a neural network called Auriga to robustly estimate the age, extinction, and distance of a stellar group based on the input photometry and parallaxes of the individual members. We apply Auriga to derive the properties of not only the structures found in this paper, but also previously identified open clusters. Through this work, we examine the temporal structure of the spiral arms. Specifically, we find that the Sagittarius arm has moved by >500 pc in the last 100 Myr, and the Perseus arm has been experiencing a relative lull in star formation activity over the last 25 Myr. We confirm the findings from the previous paper on the transient nature of the spiral arms, with the timescale of transition of a few 100 Myr. Finally, we find a peculiar ~1 Gyr old stream of stars that appears to be heliocentric. It is unclear what is the origin of it.
