标题： 盖亚早期数据释放3：来自盖亚DR2的更新径向速度 显示英文标题

标题： Gaia Early Data Release 3: Updated radial velocities from Gaia DR2

摘要： 盖亚的早期第三数据发布（EDR3）不包含新的视向速度，因为这些将在盖亚的完整第三数据发布（DR3）中发表，预计在2022年上半年。为了最大化EDR3的有用性，盖亚的第二数据发布（DR2）源（带有视向速度）与EDR3源匹配，以允许其DR2视向速度也包含在EDR3中。这带来了两个考虑因素：(i) arXiv:1901.10460（以下简称B19）发表了一个包含70,365个可能被污染的DR2视向速度源的列表；以及(ii) EDR3基于一个新的天体测量解决方案和一个新的源列表，这意味着DR2中的源可能不在EDR3中。EDR3包含7,209,831个带有DR2视向速度的源，这是DR2中具有视向速度的源的99.8%。14,800个来自DR2的视向速度未传递到任何EDR3源，因为(i) B19列表中的3871个源被发现要么没有未发布的初步DR3视向速度，或者其与DR2值有显著差异，以及5颗高速恒星不在B19列表中，被确认具有污染的视向速度；以及(ii) 10,924个DR2源无法与任何EDR3源进行令人满意地匹配，因此它们的DR2视向速度也缺失于EDR3。与DR2相比，EDR3中的视向速度可靠性有所提高，因为更新移除了少量错误的视向速度（占DR2视向速度的0.05%和B19列表的5.5%）。从EDR3中学到的经验（例如明亮恒星污染）将改善未来盖亚数据发布中的视向速度。DR2的视向速度未传递到EDR3的主要原因是与DR2视向速度质量无关。这是因为DR2的天体测量基于密近双星对的一个成分，而EDR3的天体测量基于另一个成分，这使得这些源无法明确匹配。（摘要） 显示英文摘要

摘要： Gaia's Early Third Data Release (EDR3) does not contain new radial velocities because these will be published in Gaia's full third data release (DR3), expected in the first half of 2022. To maximise the usefulness of EDR3, Gaia's second data release (DR2) sources (with radial velocities) are matched to EDR3 sources to allow their DR2 radial velocities to also be included in EDR3. This presents two considerations: (i) arXiv:1901.10460 (hereafter B19) published a list of 70,365 sources with potentially contaminated DR2 radial velocities; and (ii) EDR3 is based on a new astrometric solution and a new source list, which means sources in DR2 may not be in EDR3. EDR3 contains 7,209,831 sources with a DR2 radial velocity, which is 99.8% of sources with a radial velocity in DR2. 14,800 radial velocities from DR2 are not propagated to any EDR3 sources because (i) 3871 from the B19 list are found to either not have an unpublished, preliminary DR3 radial velocity or it differs significantly from its DR2 value, and 5 high-velocity stars not in the B19 list are confirmed to have contaminated radial velocities; and (ii) 10,924 DR2 sources could not be satisfactorily matched to any EDR3 sources, so their DR2 radial velocities are also missing from EDR3. The reliability of radial velocities in EDR3 has improved compared to DR2 because the update removes a small fraction of erroneous radial velocities (0.05% of DR2 radial velocities and 5.5% of the B19 list). Lessons learnt from EDR3 (e.g. bright star contamination) will improve the radial velocities in future Gaia data releases. The main reason for radial velocities from DR2 not propagating to EDR3 is not related to DR2 radial velocity quality. It is because the DR2 astrometry is based on one component of close binary pairs, while EDR3 astrometry is based on the other component, which prevents these sources from being unambiguously matched. (Abridged)