Velocity-space substructures and bar resonances in an <i>N</i>-body Milky Way
Velocity-space substructures and bar resonances in an <i>N</i>-body Milky Way
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<i>N</i>体银河系中的速度空间子结构和条共振
DOI：
10.1017/s1743921322001521
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Portegies Zwart Simon
中科院分区：
文献类型：
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作者：
Asano Tetsuro;Fujii Michiko S.;Baba Junich;B?dorf Jeroen;Sellentin Elena;Portegies Zwart Simon
太阳邻星的速度空间分布显示出复杂的子结构（移动群），包括著名的大力士流。最近，盖亚观测揭示了它们的详细结构，但它们的起源仍然存在争议。我们分析了类银河系 (MW) 的高分辨率 N 体模拟。为了找到与太阳邻星相似的速度空间分布，我们使用了 Kullback-Leibler 散度 (KLD)，这是一种衡量概率分布之间相似性的度量。 KLD 分析显示了速度-空间分布的时间演化和空间变化。在模拟 MW 中经常但并不总是检测到具有小 KLD（即高相似性）的速度空间分布。在具有最小 KLD 的速度图中，速度空间子结构由条共振构成。
The velocity-space distribution of the solar neighborhood stars shows complex substructures (moving groups) including the well-known Hercules stream. Recently, the Gaia observation revealed their detailed structures, but their origins are still in debate. We analyzed a high-resolution N-body simulation of a Milky Way (MW)-like galaxy. To find velocity-space distributions similar to that of the solar neighborhood stars, we used Kullback-Leibler divergence (KLD), which is a metric to measure similarities between probability distributions. The KLD analysis shows the time evolution and the spatial variation of the velocity-space distribution. Velocity-space distributions with small KLDs (i.e. high similarities) are frequently but not always detected around in the simulated MW. In the velocity-map with smallest KLD, the velocity-space substructures are made from bar resonances.