论文标题

描述了Radcliffe Wave中年轻恒星的3D运动学

Characterizing the 3D Kinematics of Young Stars in the Radcliffe Wave

论文作者

Tu, Alan J., Zucker, Catherine, Speagle, Joshua S., Beane, Angus, Goodman, Alyssa, Alves, João, Faherty, Jacqueline, Burkert, Andreas

论文摘要

我们介绍了Radcliffe Wave的运动学的分析,Radcliffe Wave是一种在最近通过3D粉尘映射检测到的太阳邻域中的2.7 kpc较长的正弦带。使用Gaia DR2天文学和光谱法,我们使用波浪新出生的星星的运动作为其气体运动的代理,将$ \ sim 1500 $ sim 1500 $年轻恒星的3D空间速度分析。我们发现,年轻恒星的垂直角 - 对应于垂直于银河平面的轨道相的垂直角,随着沿结构的位置的函数而有很大变化,其模式可能与波浪样振荡一致。这种振荡在来自盖亚(Gaia)的较老恒星的对照样本中没有看到相同体积,由长寿命的物理过程引起的相同体积,不扩展的地层通道。我们使用``波浪中的平面''模型来解释年轻恒星中看到的垂直角度的趋势,并发现虽然波浪空间周期和振幅的最佳拟合参数在质量上与由3D粉尘定义的现有形态一致,但没有证据表明额外的速度结构。这些结果支持在Radcliffe波的形成中更近的和/或短暂过程,这将主要影响波浪气态材料的运动。将结果与新的和即将进行的新模拟进行比较,并结合Gaia DR3中的新出现的径向速度测量值,应该使我们能够进一步区分各种竞争假设。

We present an analysis of the kinematics of the Radcliffe Wave, a 2.7-kpc-long sinusoidal band of molecular clouds in the solar neighborhood recently detected via 3D dust mapping. With Gaia DR2 astrometry and spectroscopy, we analyze the 3D space velocities of $\sim 1500$ young stars along the Radcliffe Wave in action-angle space, using the motion of the wave's newly born stars as a proxy for its gas motion. We find that the vertical angle of young stars -- corresponding to their orbital phase perpendicular to the Galactic plane -- varies significantly as a function of position along the structure, in a pattern potentially consistent with a wave-like oscillation. This kind of oscillation is not seen in a control sample of older stars from Gaia occupying the same volume, disfavouring formation channels caused by long-lived physical processes. We use a ``wavy midplane'' model to try to account for the trend in vertical angles seen in young stars, and find that while the best-fit parameters for the wave's spatial period and amplitude are qualitatively consistent with the existing morphology defined by 3D dust, there is no evidence for additional velocity structure. These results support more recent and/or transitory processes in the formation of the Radcliffe Wave, which would primarily affect the motion of the wave's gaseous material. Comparisons of our results with new and upcoming simulations, in conjunction with new stellar radial velocity measurements in Gaia DR3, should allow us to further discriminate between various competing hypotheses.

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