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arXiv 2310.09331astro-ph.GAastro-ph.SR
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银河系GEMS星表:球状星团潮外模拟恒星

A catalogue of Galactic GEMS: Globular cluster Extra-tidal Mock Stars

Steffani M. Grondin, Jeremy J. Webb, James M. M. Lane, Joshua S. Speagle, Nathan W. C. Leigh

AI总结:

本文构建了GEMS星表,通过Corespray模拟159个银河系球状星团中因三体作用逃逸的潮外恒星与双星,并利用作用量坐标实现场星与宿主星团的概率匹配,为研究星团动力学演化提供关键工具。

摘要:

本工作提出了球状星团潮外模拟恒星(GEMS)星表,该星表收录了球状星团核心中通过三体动力学相互作用产生的潮外恒星和双星。利用粒子喷洒代码Corespray,我们为159个银河系球状星团采样了N=50,000颗潮外恒星和逃逸的反冲双星。所有模拟恒星均提供了天空位置、运动学、恒星性质以及逃逸信息。恒星轨道在七个不同的静态和时变银河系引力势模型中进行了积分,其中盘的结构、来自大麦哲伦云的扰动以及银河系暗物质晕的质量和球度均被研究。我们发现模拟潮外恒星的作用量坐标在很大程度上与银河系模型无关,模型之间分布的微小偏移和展宽可能源于与子结构的相互作用。重要的是,我们还首次报告了对于近心点半径大于五千秒差距的星团,球状星团核心恒星和双星对恒星流造成污染的证据。最后,我们提供了一个定量工具,利用作用量坐标将场星与宿主星团进行概率匹配。最终,将GEMS星表的数据与观测恒星的信息相结合,将能够把潮外场星与任何银河系球状星团关联起来;这是理解银河系中星团种群级动力学和演化的必要工具。

英文摘要:

This work presents the Globular cluster Extra-tidal Mock Star (GEMS) catalogue of extra-tidal stars and binaries created via three-body dynamical encounters in globular cluster cores. Using the particle-spray code Corespray, we sample N=50,000 extra-tidal stars and escaped recoil binaries for 159 Galactic globular clusters. Sky positions, kinematics, stellar properties and escape information are provided for all simulated stars. Stellar orbits are integrated in seven different static and time-varying Milky Way gravitational potential models where the structure of the disc, perturbations from the Large Magellanic Cloud and the mass and sphericity of the Milky Way's dark matter halo are all investigated. We find that the action coordinates of the mock extra-tidal stars are largely Galactic model independent, where minor offsets and broadening of the distributions between models are likely due to interactions with substructure. Importantly, we also report the first evidence for stellar stream contamination by globular cluster core stars and binaries for clusters with pericentre radii larger than five kiloparsecs. Finally, we provide a quantitative tool that uses action coordinates to match field stars to host clusters with probabilities. Ultimately, combining data from the GEMS catalogue with information of observed stars will allow for association of extra-tidal field stars with any Galactic globular cluster; a requisite tool for understanding population-level dynamics and evolution of clusters in the Milky Way.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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