论文标题
Gaia Edr3在6D中：在银河系中寻找未结合的星星
Gaia EDR3 in 6D: Searching for unbound stars in the Galaxy
论文作者
论文摘要
欧洲航天局卫星盖亚（Gaia）的第三个数据发布（EDR3）根据34个月的观察，以我们的银河系来提供约14.7亿个来源的坐标，视差和适当的动议。 GAIA DR2径向速度与Gaia EDR3提供的更精确和准确的天文统计的组合使最佳数据集可用于搜索我们银河系中最快的附近恒星。我们计算了具有精确视差的约700万颗恒星的速度分布，以研究以银河系方式的恒星速度分布的高速尾部。我们发布了一个具有距离，总速度的目录，以及我们分析中考虑的所有星星的相应不确定性，请访问https://sites.google.com/view/tmarchetti/research。通过在GAIA天文统计和径向速度上施加质量削减，我们确定了94颗恒星的干净子集，概率> 50％与我们的银河系无束缚。其中17个酒吧> 80％，是我们最好的候选人。我们在银河系中传播了这些恒星，以表征它们的轨道。我们发现11颗恒星与从银河系磁盘弹出的一致，并且可能是超级跑步的恒星候选者。其他6颗恒星与来自已知的恒星形成区域不一致。我们研究了采用视差零点校正的效果，这对我们的结果产生了强烈影响：应用此校正时，我们仅识别出12颗恒星> 50％，其中3个具有pub> 80％。需要进行地面望远镜的光谱随访，以确认这项工作中确定的候选人。
The early third data release (EDR3) of the European Space Agency satellite Gaia provides coordinates, parallaxes, and proper motions for ~1.47 billion sources in our Milky Way, based on 34 months of observations. The combination of Gaia DR2 radial velocities with the more precise and accurate astrometry provided by Gaia EDR3 makes the best dataset available to search for the fastest nearby stars in our Galaxy. We compute the velocity distribution of ~7 million stars with precise parallaxes, to investigate the high-velocity tail of the velocity distribution of stars in the Milky Way. We release a catalogue with distances, total velocities, and corresponding uncertainties for all the stars considered in our analysis, available at https://sites.google.com/view/tmarchetti/research . By applying quality cuts on the Gaia astrometry and radial velocities, we identify a clean subset of 94 stars with a probability Pub > 50% to be unbound from our Galaxy. 17 of these have Pub > 80% and are our best candidates. We propagate these stars in the Galactic potential to characterize their orbits. We find that 11 stars are consistent with being ejected from the Galactic disk, and are possible hyper-runaway star candidates. The other 6 stars are not consistent with coming from a known star-forming region. We investigate the effect of adopting a parallax zero point correction, which strongly impacts our results: when applying this correction, we identify only 12 stars with Pub > 50%, 3 of these having Pub > 80%. Spectroscopic follow-ups with ground-based telescopes are needed to confirm the candidates identified in this work.
