论文标题
开放簇作为银河系磁盘径向迁移的示踪剂
Open Clusters as Tracers on Radial Migration of the Galactic Disk
论文作者
论文摘要
径向迁移是银河系磁盘中的重要过程。一些开放式簇显示了有关此机制的一些证据，但是没有系统的研究。在这项工作中，我们根据Netopil等人的146个具有均匀金属性的146个开放式簇的样本研究了径向迁移在银河盘上的作用。并根据GAIA DR2计算的运动学。计算出生地RB，指导半径RG和其他轨道参数，并迁移距离| RG-RB |获得，这是金属性，运动学和年龄信息的组合。发现有44％的开放簇具有| RG-RB | <1 kpc，对于radial迁移（搅动）并不重要。在其余的56％的开放式群集中，| RG-RB |> 1 kpc，t <1.0 Gyr的年轻人倾向于向内迁移，而较旧的簇通常会向外迁移。根据年轻群体和年龄簇之间的径向迁移的不同机制，根据其不同的迁移率，银河系位置和轨道参数。对于旧组，我们提出了一种合理的方法来估计迁移率，并基于外部磁盘上的十个中级年龄群的合理值1.5（+-0.5）kpc/gyr，其中几个特殊簇的存在意味着其复杂的形成历史。
Radial migration is an important process in the Galactic disk. A few open clusters show some evidence on this mechanism but there is no systematic study. In this work, we investigate the role of radial migration on the Galactic disk based on a large sample of 146 open clusters with homogeneous metallicity and age from Netopil et al. and kinematics calculated from Gaia DR2. The birth site Rb, guiding radius Rg and other orbital parameters are calculated, and the migration distance |Rg-Rb| is obtained, which is a combination of metallicity, kinematics and age information. It is found that 44% open clusters have |Rg-Rb|< 1 kpc, for which radial migration (churning) is not significant. Among the remaining 56% open clusters with |Rg-Rb|> 1 kpc, young ones with t<1.0 Gyr tend to migrate inward, while older clusters usually migrate outward. Different mechanisms of radial migration between young and old clusters are suggested based on their different migration rates, Galactic locations and orbital parameters. For the old group, we propose a plausible way to estimate migration rate and obtain a reasonable value of 1.5(+-0.5) kpc/Gyr based on ten intermediate-age clusters at the outer disk, where the existence of several special clusters implies its complicate formation history.
