论文标题
使用GAIA DR2和HST数据的球状簇运动学的银河系子系统
Milky Way Subsystems from Globular Clusters Kinematics Using Gaia DR2 and HST Data
论文作者
论文摘要
我们采用GAIA DR2适当的动作，以与Vasiliev（2019）的151 MiLky Way Glogular簇同行，距离距离和视线速度有距离和视线速度。为了将簇分配到银河系厚的磁盘，凸起和光晕，我们遵循Posti等人的方法。 （2018年），他使用恒星轨道区分了不同的银河恒星组件。特别是，我们使用比率$ l_ {z}/e $，$ z $的$ z $投影对偏心率，作为种群示踪剂，我们与从文献和蒙特卡洛模拟中提取的化学丰度相辅相成。我们发现，20个球状簇属于银河系的条/凸起，35个展示磁盘性能，而96个是光环的成员。此外，我们发现光晕球形簇的旋转速度接近零旋转速度，平均值$ <θ>$ = 1 $ \ pm $ 4 km S $^{ - 1} $。另一方面，属于厚磁盘的簇样品具有显着的旋转，平均旋转速度179 $ \ pm $ 6 km s $^{ - 1} $。银河系的酒吧/凸起区域内绕的二十个球状簇的平均旋转速度为49 $ \ pm $ \ $ 11 km S $^{ - 1} $。
We employ Gaia DR2 proper motions for 151 Milky Way globular clusters from Vasiliev (2019) in tandem with distances and line-of-sight velocities to derive their kinematical properties. To assign clusters to the Milky Way thick disk, bulge, and halo we follow the approach of Posti et al. (2018) who distinguished among different Galactic stellar components using stars's orbits. In particular, we use the ratio $L_{z}/e$, the $Z$ projection of the angular momentum to the eccentricity, as population tracer, which we complement with chemical abundances extracted from the literature and Monte-Carlo simulations. We find that 20 globular clusters belong to the bar/bulge of the Milky Way, 35 exhibit disk properties, and 96 are members of the halo. Moreover, we find that halo globular clusters have close to zero rotational velocity with average value $<Θ>$ =1$\pm$ 4 km s$^{-1}$. On the other hand, the sample of clusters that belong to the thick disk possesses a significant rotation with average rotational velocity 179 $\pm$ 6 km s$^{-1}$. The twenty globular clusters orbiting within the bar/bulge region of the Milky Way galaxy have average rotational velocity of 49 $\pm$ 11 km s$^{-1}$.
