标题： 太阳邻域中Gaia DR2的高速运动集团 显示英文标题

标题： High-velocity moving groups in the Solar neighborhood in Gaia DR2

摘要： 我们使用改进的小波分析技术，从盖亚数据释放2中位于太阳邻域约$200$pc范围内的$\sim 250000$恒星重建$(U,V,W)$速度分布。 对三个双变量分布$(U,V)$、$(U,W)$和$(V,W)$进行了二维小波变换研究。 尽管目前已知的（低速）恒星运动集团在这些图中大部分密集重叠，但我们的分析使得检测和区分大约二十个统计显著的三维高速恒星集团成为可能。 其中大多数是新的。 我们还讨论了小波变换中正确噪声阈值设置的问题，并强调使用全局统计量而非局部统计量的重要性。 使用局部显著性度量可能导致由于多重检验效应而高估个别模式的统计置信度。 显示英文摘要

摘要： We use an improved wavelet analysis technique to reconstruct the $(U,V,W)$ velocity distribution for $\sim 250000$ stars from Gaia DR2, residing in the solar neighborhood of $200$~pc. The 2D wavelet transforms for three bivariate distributions $(U,V)$, $(U,W)$, and $(V,W)$ were investigated. Though most of currently known (low-velocity) stellar moving groups are densely overlapped in these diagrams, our analysis allowed to detect and disentangle about twenty statistically significant 3D groups of stars with high velocities. Most of them appear new. We also discuss the issue of correct noise thresholding in the wavelet transform and highlight the importance of using a global rather than local statistic for that. Using of a local significance measure may lead to an overstated statistical confidence for individual patterns due to the effect of multiple testing.