Kinematical evolution of multiple stellar populations in star clusters
Kinematical evolution of multiple stellar populations in star clusters
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星团中多个恒星群的运动演化
DOI：
10.1093/mnras/stz1595
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发表时间：
2019
影响因子：
4.8
通讯作者：
A. L.
中科院分区：
文献类型：
--
作者：
Tiongco;M.;Vesperini;E.;Varri;A. L.
我们提出了一套ofN体模拟的结果，旨在了解球状星团中的多个恒星种群的内部运动学的长期演化的基本方面。我们的模型使我们能够研究内部的，弛豫驱动的过程和外部的，潮汐引起的扰动的结构和运动学性质的多人口球状星团的合作效果。为了分析在各种自旋轨道耦合条件下的多个恒星种群的动力学行为，我们考虑了三个参考案例，其中潮汐扰动星星集群旋转沿着一个相对于轨道角动量矢量在不同方向取向的轴。我们专注于具体的速度空间中的微分旋转和各向异性的程度的演变的表征，我们量化的两个人口的空间和运动学混合的过程。根据最近和即将到来的探索这类恒星系统的内部运动学的视线和天体测量的手段，我们还调查的影响，投影效应和空间分布的恒星作为示踪剂。从我们的模型中出现的运动学和结构的丰富性进一步强调了观测研究的必要性和重要性，旨在建立一个完整的运动学图片的多人口现象。
We present the results of a suite ofN-body simulations aimed at understanding the fundamental aspects of the long-term evolution of the internal kinematics of multiple stellar populations in globular clusters. Our models enable us to study the cooperative effects of internal, relaxation-driven processes and external, tidally induced perturbations on the structural and kinematic properties of multiple-population globular clusters. To analyse the dynamical behaviour of the multiple stellar populations in a variety of spin-orbit coupling conditions, we have considered three reference cases in which the tidally perturbed star cluster rotates along an axis oriented in different directions with respect to the orbital angular momentum vector. We focus specifically on the characterization of the evolution of the degree of differential rotation and anisotropy in the velocity space, and we quantify the process of spatial and kinematic mixing of the two populations. In light of recent and forthcoming explorations of the internal kinematics of this class of stellar systems by means of line-of sight and astrometric measurements, we also investigate the implications of projection effects and spatial distribution of the stars adopted as tracers. The kinematic and structural richness emerging from our models further emphasizes the need and the importance of observational studies aimed at building a complete kinematical picture of the multiple population phenomenon.