论文标题
Cygnus中OB恒星的大规模扩展
Large-scale expansion of OB stars in Cygnus
论文作者
论文摘要
最近发现，Cygnus中OB恒星的适当运动（PMS）表现出两种大规模的运动学模式。我们对这些OB恒星，新识别的OB关联以及该地区相关的开放群集进行3D追溯。我们发现有两组恒星，关联和集群，并且它们过去均更加紧凑，达到了最接近的方法$ 7.9^{+3.0} _ { - 1.8} $和$ 8.5^{+0.8} _ { - 2.8} $ Myr Ago。我们考虑了这些大规模膨胀模式的驱动因素的两个主要情况：从上一代巨大的恒星中驱动反馈驱动的扩展，以及由于原始分子云中的湍流速度场而扩展。尽管很容易将这种大规模扩展模式归因于反馈过程，但我们发现观察到的运动学与湍流起源完全一致，因此不需要从反馈中注入进一步的能量或动量。对于具有大规模扩展模式的其他恒星形成区域，可能会得出类似的结论。
The proper motions (PMs) of OB stars in Cygnus have recently been found to exhibit two large-scale kinematic patterns suggestive of expansion. We perform a 3D traceback on these OB stars, the newly-identified OB associations and related open clusters in the region. We find that there are two groups of stars, associations and clusters and that they were each more compact in the past, reaching their closest approach $7.9^{+3.0}_{-1.8}$ and $8.5^{+0.8}_{-2.8}$ Myr ago. We consider two main scenarios for the driver of these large-scale expansion patterns: feedback-driven expansion from a previous generation of massive stars, and expansion as a result of the turbulent velocity field in the primordial molecular cloud. While it is tempting to attribute such large-scale expansion patterns to feedback processes, we find that the observed kinematics are fully consistent with the turbulent origin, and therefore that the injection of further energy or momentum from feedback is not required. Similar conclusions may be drawn for other star forming regions with large-scale expansion patterns.
