Abstract

This work is devoted to studying the influence of the bar on the orbital dynamics of globular clusters. The orbits of 45 globular clusters in the central galactic region with a radius of 3.5 kpc were analyzed using spectral dynamics methods in order to identify objects captured by the bar. To form the 6D phase space required for orbit integration, the most accurate astrometric data to date from the Gaia satellite (EDR3), as well as new refined average distances to globular clusters, were used. Since the parameters of the Milky Way bar are known with very great uncertainty, the orbits were constructed and their frequency analysis was carried out by varying the mass, length and angular velocity of rotation of the bar in a wide range of values with a fairly small step. The integration of orbits was carried out at 2.5 billion years ago. As a result, bar-supporting globular clusters were identified for each set of bar parameters. For the first time, an analytical expression has been obtained for the dependence of the dominant frequency \(f_{X}\) on the angular velocity of rotation of the bar. In addition, the probabilities of globular clusters being captured by the bar were determined when the bar parameters were varied in certain ranges of values according to a random distribution law. A list of 14 globular clusters with the most significant capture probabilities is given, with five GCs—NGC 6266, NGC 6569, Terzan 5, NGC 6522, NGC 6540—showing the probability of capture by the bar \(P\geq 0.2\). A conclusion is made about the regularity of the orbits of globular clusters based on the calculation of approximations of the maximum characteristic Lyapunov exponents.

中文翻译：

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棒对银河系中央区域球状星团动力学的影响。根据 Gaia EDR3 数据进行轨道频率分析

摘要

这项工作致力于研究棒对球状星团轨道动力学的影响。为了识别棒捕获的物体，利用光谱动力学方法对银河系中心区域半径为 3.5 kpc 的 45 个球状星团的轨道进行了分析。为了形成轨道积分所需的 6D 相空间，使用了迄今为止来自盖亚卫星 (EDR3) 的最准确的天体测量数据，以及到球状星团的新的精确平均距离。由于银河系棒的参数已知具有很大的不确定性，因此通过在相当大的范围内改变棒的质量、长度和旋转角速度来构造轨道并进行频率分析，并且具有相当小的值。步。轨道整合是在25亿年前进行的。结果，为每组棒材参数识别了支撑棒材的球状星团。首次获得了主频率\(f_{X}\)对棒旋转角速度依赖性的解析表达式。此外，当棒参数根据随机分布规律在一定的值范围内变化时，确定了棒捕获球状星团的概率。给出了具有最显着捕获概率的 14 个球状星团的列表，其中有 5 个 GC——NGC 6266、NGC 6569、Terzan 5、NGC 6522、NGC 6540——显示条形捕获的概率 \ (P\geq 0.2\)。通过计算最大特征李雅普诺夫指数的近似值，得出球状星团轨道规律性的结论。