Searching for young runaways across the sky
Searching for young runaways across the sky
复制标题
跨越天空寻找逃亡少年
DOI：
10.1093/mnras/stac2829
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发表时间：
2022
影响因子：
4.8
通讯作者：
Leigh, Nathan
中科院分区：
文献类型：
--
作者：
Kounkel, Marina;Mcbride, Aidan;Stassun, Keivan G;Leigh, Nathan
我们提供了一个包含3354颗500 pc以内的候选年轻恒星的星表，这些恒星似乎是以大于5 km s−1的相对速度从它们的母星协中被抛射出来的。这些候选者是通过对先前识别的主序前候选者进行二维球形回溯到各个恒星形成区域来均匀选择的，确保回溯年龄以及星星的估计年龄与人口年龄一致，并排除来自遵循场中主导速度流的附近移动群体的污染物。在已确定的候选者中，我们确定了一些似乎在弹射过程中相互作用的对;这些对具有相似的回溯时间，并且它们的轨迹似乎彼此完全相反，或者它们在这个过程中形成了一个宽的二进制。由于这些候选者的选择仅在2D中执行，因此光谱跟踪对于它们的最终确认是必要的。不幸的是，最近公布的GaiaDR 3径向速度似乎不适合描述年龄小于1亿年的低质量恒星的运动学特征，因为吸积，活动和各种其他光谱特征使它们与更演化的恒星不同，这些特征似乎没有在数据中得到准确的解释，导致其RV分布中显着的人为膨胀散射。
We present a catalogue of 3354 candidate young stars within 500 pc that appear to have been ejected from their parent associations with relative speeds of >5 km s−1. These candidates have been homogeneously selected through performing a 2D spherical traceback of previously identified pre-main-sequence candidates to various star-forming regions, ensuring that the traceback age as well as the estimated age of a star is consistent with the age of the population, and excluding contaminants from the nearby moving groups that follow the dominant velocity currents in the field. Among the identified candidates we identify a number of pairs that appear to have interacted in the process of the ejection; these pairs have similar traceback time, and their trajectory appears to be diametrically opposite from each other, or they have formed a wide binary in the process. As the selection of these candidates is performed solely in 2D, spectral follow-up is necessary for their eventual confirmation. Unfortunately, recently releasedGaiaDR3 radial velocities appear to be unsuitable for characterizing the kinematics of low-mass stars with ages <100 Myr, as the accretion, activity, and a variety of other spectral features that make them distinct from the more evolved stars do not appear to have been accurately accounted for in the data, resulting in significant artificially inflated scatter in their RV distribution.