The eye of Gaia on globular clusters kinematics: internal rotation
The eye of Gaia on globular clusters kinematics: internal rotation
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盖亚之眼关于球状星团运动学：内旋转
DOI：
10.1093/mnras/stz505
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发表时间：
2019
影响因子：
4.8
通讯作者：
M. Hilker
中科院分区：
文献类型：
--
作者：
A. Sollima;H. Baumgardt;M. Hilker
我们利用盖亚任务第二次数据发布的适当运动，以及最全面的视距速度集，得出了62个银河系球状星团样本中单个恒星的三维速度，目的是研究这些恒星系统的旋转模式。我们在15个集群中检测到明确的旋转信号，其振幅远远高于随机和系统误差的水平。对于这些集群，我们推导出了旋转轴相对于视线的位置和倾角，以及旋转对总动能预算的总体贡献。旋转强度与半质量半径、弛豫时间呈弱相关，与破坏率呈负相关，而旋转轴与轨道极没有明显的对齐。这一证据指向了这些恒星系统中系统旋转的原始起源。
We derived the three-dimensional velocities of individual stars in a sample of 62 Galactic globular clusters using proper motions from the second data release of the Gaia mission together with the most comprehensive set of line-of-sight velocities with the aim of investigating the rotation pattern of these stellar systems. We detect the unambiguous signal of rotation in 15 clusters at amplitudes which are well above the level of random and systematic errors. For these clusters, we derived the position and inclination angle of the rotation axis with respect to the line of sight and the overall contribution of rotation to the total kinetic energy budget. The rotation strengths are weakly correlated with the half-mass radius, the relaxation time, and anticorrelated with the destruction rate, while no significant alignment of the rotation axes with the orbital poles has been observed. This evidence points towards a primordial origin of the systemic rotation in these stellar systems.