论文标题
Alpha Persei星团与附近的恒星流的关系
The relation of the Alpha Persei star cluster with the nearby stellar stream
论文作者
论文摘要
从Gaia Dr2提取并以Alpha Persei为中心的侧面的100度图显示了两个不同的结构|正如最近文献中广泛记录的那样，Alpha Persei星团和引人注目的恒星流。在这项工作中，我们采用DBSCAN来评估单个恒星的成员资格，并尝试将属于群集和溪流的恒星与一般领域分开。反过来，我们表征流并研究其与群集的关系。事实证明，溪流人群比集群大得多（5 +/- 1GYR），在其背景下，距离群集约90 pc。该流在视线方向上表现出〜180 pc的巨大厚度。最后，溪流拥有著名的白矮星人。我们估计〜6000太阳能的流质量的上限？因此，该流将是一个相对较大的旧集群的剩余。 Alpha Persei的表面密度图证明了潮汐尾巴的存在。虽然很容易将它们归因于破坏的老星团的互动，但我们宁愿保守地相信它们是银河系的起源。
A map of 100 degrees on a side extracted from Gaia DR2 and centred on Alpha Persei reveals two distinct structures | the Alpha Persei star cluster and a conspicuous stellar stream, as widely documented in recent literature. In this work we employ DBSCAN to assess individual stars' membership and attempt at separating stars belonging to the cluster and to the stream from the general field. In turn, we characterize the stream and investigate its relation with the cluster. The stream population turned out to be significantly older (5+/-1Gyr) than the cluster, and to be positioned ~90 pc away from the cluster, in its background. The stream exhibits a sizeable thickness of ~180 pc in the direction of the line of view. Finally, the stream harbours a prominent population of white dwarf stars. We estimated an upper limit of the stream mass of ~6000 solar masses?. The stream would therefore be the leftover of a relatively massive old cluster. The surface density map of the Alpha Persei evidences the presence of tidal tails. While it is tempting to ascribe them to the interaction with the disrupting old star cluster, we prefer to believe, conservatively, they are of Galactic origin.
