论文标题
联合恒星流数据的动作空间中的聚类中的银河电位约束
Galactic potential constraints from clustering in action space of combined stellar stream data
论文作者
论文摘要
潮汐从其祖细胞卫星星系或球状簇从邻近轨道上的一组测试粒子起作用，探测了银河系的重力场。尽管已经显示出来自单个流的限制容易受到偏见的影响，但结合了来自各个距离的轨道的几条流可减少这些偏见。我们通过在动作空间中最大化流星的聚类来同时拟合多个恒星流的共同引力潜力。我们将此技术应用于GD-1，PAL 5，Orphan和Helmi流的成员，从而利用了个人和组合数据集。我们使用Stäckel模型描述银河电位，并同时改变五个参数。我们发现我们只能约束封闭的质量，最强的约束来自GD-1，PAL 5和孤儿流，其组合数据集产生$ m（<20 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ kpc}）= 2.96^{+0.25} _ {+0.25} _ { - 0.26} \ 0.26} \ times times 10^{11}} $ _______________当在数据集中加入Helmi流时，质量不确定性会增加到$ m（<20 \ \ \ \ \ \ mathrm {kpc}）= 3.12^{+3.21} _ { - 0.46} \ times 10^{11} {11}} \ m _ {\ m _ {\ odot} $。
Stream stars removed by tides from their progenitor satellite galaxy or globular cluster act as a group of test particles on neighboring orbits, probing the gravitational field of the Milky Way. While constraints from individual streams have been shown to be susceptible to biases, combining several streams from orbits with various distances reduces these biases. We fit a common gravitational potential to multiple stellar streams simultaneously by maximizing the clustering of the stream stars in action space. We apply this technique to members of the GD-1, Pal 5, Orphan and Helmi streams, exploiting both the individual and combined data sets. We describe the Galactic potential with a Stäckel model, and vary up to five parameters simultaneously. We find that we can only constrain the enclosed mass, and that the strongest constraints come from the GD-1, Pal 5 and Orphan streams whose combined data set yields $M(< 20\ \mathrm{kpc}) = 2.96^{+0.25}_{-0.26} \times 10^{11} \ M_{\odot}$. When including the Helmi stream in the data set, the mass uncertainty increases to $M(< 20\ \mathrm{kpc}) = 3.12^{+3.21}_{-0.46} \times 10^{11} \ M_{\odot}$.
