In this paper, we report 591 high-velocity star candidates (HiVelSCs) selected from over 10 million spectra of Data Release 7 (DR7) of the Large Sky Area Multi-object Fiber Spectroscopic Telescope and the second Gaia data release, with three-dimensional velocities in the Galactic rest frame larger than 445 km s⁻¹. We show that at least 43 HiVelSCs are unbound to the Galaxy with escape probabilities larger than 50%, and this number decreases to eight if the possible parallax zero-point error is corrected. Most of these HiVelSCs are metal-poor and slightly α-enhanced inner halo stars. Only 14% of them have [Fe/H]>−1, which may be the metal-rich “in situ” stars in the halo formed in the initial collapse of the Milky Way or metal-rich stars formed in the disk or bulge but kinematically heated. The low ratio of 14% implies that the bulk of the stellar halo was formed from the accretion and tidal disruption of satellite galaxies. In addition, HiVelSCs on retrograde orbits have slightly lower metallicities on average compared with those on prograde orbits; meanwhile, metal-poor HiVelSCs with [Fe/H]<−1 have an even faster mean retrograde velocity compared with metal-rich HiVelSCs. To investigate the origins of HiVelSCs, we perform orbit integrations and divide them into four types, i.e., hypervelocity stars, hyper-runaway stars, runaway stars and fast halo stars. A catalog for these 591 HiVelSCs, including radial velocities, atmospheric parameters, Gaia astrometric parameters, spatial positions, and velocities, etc., is available in the China-VO PaperData Repository atdoi:10.12149/101038.

在本文中，我们报告了591个高速候选恒星（HiVelSCs），它们是从“大天空区多目标光纤光谱望远镜”的数据发布7（DR7）和第二个盖亚数据发布的超过1000万个光谱中选择的，这些光谱具有三维特征银河静止框架中的速度大于445 km s ^-1。我们显示，至少有43个HiVelSC未绑定到银河，且逃逸概率大于50％，如果纠正了可能的视差零点误差，则该数字将减少到8个。这些HiVelSC中的大多数金属贫乏且α-增强了内部光晕星。其中只有14％的[Fe / H]> − 1，可能是银河系最初坍塌形成的晕圈中富含金属的“原位”星，也可能是盘状或凸起处形成的富含金属的恒星但运动加热。14％的低比率意味着大部分恒星晕是由卫星星系的积聚和潮汐破坏形成的。此外，与逆行轨道相比，逆行轨道上的HiVelSC的平均金属含量略低。同时，[Fe / H] <-1的贫金属HiVelSC与富金属HiVelSC相比具有更快的平均逆行速度。为了研究HiVelSC的起源，我们执行了轨道积分并将它们分为四种类型，即超高速恒星，超离合恒星，离合恒星和快速光晕星。这591个HiVelSC的目录，