Impact of bar resonances in the velocity-space distribution of the solar neighbourhood stars in a self-consistent N-body Galactic disc simulation
Impact of bar resonances in the velocity-space distribution of the solar neighbourhood stars in a self-consistent N-body Galactic disc simulation
复制标题
自洽 N 体银河盘模拟中棒共振对太阳邻星速度空间分布的影响
DOI：
10.1093/mnras/stac1379
复制
发表时间：
2022
影响因子：
4.8
通讯作者：
Portegies Zwart Simon
中科院分区：
文献类型：
--
作者：
Asano Tetsuro;Fujii Michiko S;Baba Junichi;Bedorf 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。以往的研究大多使用静电势来研究它们的起源。相反，我们使用的是一个自洽的银河系N体模型，它的势是不对称的，并且随着时间的推移而演变。本文用Kullback-Leibler散度(KLD)定量地评价了当时体模型中速度空间分布与太阳近邻速度空间分布的相似性。KLD分析显示了速度-空间分布的时间演化和空间变化。KLD随时间波动，这表明固定位置的速度-空间分布并不总是类似于太阳附近的速度-空间分布。一些位置的速度-空间分布具有较小的KLD(高相似性)，比其他位置更频繁。其中一个位于，其中兰特ϕ分别是离银河系中心的距离和相对于星棒长轴的角度。臂间区的检测频率高于臂间区。在具有小KLD的速度图中，我们识别了速度-空间子结构，它由捕获在条形共振中的粒子组成。尽管银河系势能不是静态的，但杆状共振对恒星速度-空间分布有很大影响。
The velocity–space distribution of the solar neighbourhood stars shows complex substructures. Most of the previous studies use static potentials to investigate their origins. Instead we use a self-consistentN-body model of the Milky Way, whose potential is asymmetric and evolves with time. In this paper, we quantitatively evaluate the similarities of the velocity–space distributions in theN-body model and that of the solar neighbourhood, using Kullback–Leibler divergence (KLD). The KLD analysis shows the time evolution and spatial variation of the velocity–space distribution. The KLD fluctuates with time, which indicates the velocity–space distribution at a fixed position is not always similar to that of the solar neighbourhood. Some positions show velocity–space distributions with small KLDs (high similarities) more frequently than others. One of them locates at, whereRand ϕ are the distance from the galactic centre and the angle with respect to the bar’s major axis, respectively. The detection frequency is higher in the inter-arm regions than in the arm regions. In the velocity maps with small KLDs, we identify the velocity–space substructures, which consist of particles trapped in bar resonances. The bar resonances have significant impact on the stellar velocity–space distribution even though the galactic potential is not static.