As ancient stellar systems, globular clusters (GCs) offer valuable insights into the dynamical histories of large galaxies. Previous studies of GC populations in the inner and outer regions of the Andromeda Galaxy (M31) have revealed intriguing subpopulations with distinct kinematic properties. Here, we build upon earlier studies by employing Bayesian modelling to investigate the kinematics of the combined inner and outer GC populations of M31. Given the heterogeneous nature of the data, we examine subpopulations defined by GCs' metallicity and by associations with substructure, in order to characterise possible relationships between the inner and outer GC populations. We find that lower-metallicity GCs and those linked to substructures exhibit a common, more rapid rotation, whose alignment is distinct from that of higher-metallicity and non-substructure GCs. Furthermore, the higher-metallicity GCs rotate in alignment with Andromeda's stellar disk. These pronounced kinematic differences reinforce the idea that different subgroups of GCs were accreted to M31 at distinct epochs, shedding light on the complex assembly history of the galaxy.

翻译：作为古老的恒星系统，球状星团（GCs）为大型星系的动力学演化史提供了宝贵线索。先前对仙女座星系（M31）内外区域球状星团群体的研究已揭示出具有独特运动学特性的有趣子群。本研究基于早期工作，采用贝叶斯建模方法对M31内外区域球状星团的综合运动学进行探究。鉴于数据的异质性，我们通过球状星团的金属丰度及其与子结构的关联性来划分子群，以刻画内外球状星团群体间可能存在的关联。研究发现，低金属丰度球状星团及与子结构关联的星团呈现出更快速且方向一致的旋转模式，其旋转轴取向与高金属丰度及非子结构星团存在显著差异。此外，高金属丰度球状星团的旋转方向与仙女座星系恒星盘的旋转方向保持一致。这些显著的运动学差异进一步印证了不同球状星团子群是在不同时期被M31吸积形成的观点，从而为理解该星系的复杂组装历史提供了新的线索。