星团系统NGC2419的运动学特征和动力学研究

星系动力学是天文学最传统且一直保持热门的研究领域之一。星团系统是构成星系的基本单元，详细研究它们有助于验证基础物理定律在天文学尺度上是否成立。经过近百年的研究，星团系统的动力学已经很成熟，但随着观测精度的不断提高，又发现了新的、难以用现有理论解释的现象。比如，银河系最遥远的大型球状星团NGC2419的外部区域恒星运动的速度弥散很小，而该星团的质量较大，内部区域恒星运动的速度弥散很大。该现象近年来得到较多研究，但仍没有令人满意的理论解释。本人将分析该星团最新的观测数据，构造一系列自洽的数值模型，检验这些模型的稳定性，筛选出稳定的模型。再应用与观测数据相结合的粒子模拟方法，使它们逐步演化到与观测结果符合的状态，再次检验模型终态的稳定性，并对模型中的物理特征量做时间积分，系统地研究恒星在星团系统中的运动学性质。在这些工作的基础上，继续深入探索，研究NGC 2419星团反常观测现象背后的物理机制。

Galactic dynamics is one of the most classical and popular research areas in astronomy. It is known that star clusters are the basic units of the galaxies. To test the fundamental physical laws at the astronomical scale, it is very helpful to study the properties of star clusters. The complicated dynamics of star clusters have been extensively investigated for over one hundred years. Thanks to the continuous improvement of the resolution of observations, a plenty of new phenomena have been discovered in the past decade, many of which are exotic and hard to understand within the existing dynamical models. In particular, recently it has been observed that the velocity dispersion of the stars in the outer regime of the massive globular cluster, NGC 2419, which is one of the most distant star cluster of the Milky Way Galaxy, is very small, while the velocity dispersion of the stars in the inner regime of NGC 2419 is very large. We shall analyse the latest observational data and construct a series of self-consistent numerical models of NGC 2419. We shall test the stability of these models and select the stable ones. Then we shall perform the particle made-to-measure method to evolve the models until they arrive the status which agree with the observations. The stability of the final products will be test as well. Based on the above simulations, the kinematic observables in the models will be temporally integrated to smooth the data in the models. Therefore, the kinematic properties of the stars in NGC 2419-like star clusters will be better studied. Besides, the possibility and the influence of the existence of a black hole in NGC 2419 will be studied. The physical mechanism of NGC 2419 will be discussed and be better understood via the above study.