论文标题
猎户座云配合物的3D动力学 - 在100 pc量表中发现相干径向气体运动
3D dynamics of the Orion cloud complex -- Discovery of coherent radial gas motions at the 100-pc scale
论文作者
论文摘要
我们介绍了整个南部猎户座云配合物中气体3D动力学的首次研究。我们使用了Gaia DR2的YSO的视差和适当的运动作为气体距离和适当运动的代理，以及来自档案CO数据的气体径向速度，以计算综合体中不同星形云的空间运动，包括Orion A，Orion A，Orion B中的子区域，以及两个偶然的cometare cometare cometare cometary Clouds。从对时空中云的轨道的分析，我们发现它们是大约6 Myr的最接近的云，并且径向移动到空间中的大致相同区域。这种连贯的100-pc刻度径向运动支持整个复合物对重大反馈事件的反应的情况，我们将其命名为Orion-BB（Big Blast）事件。我们暂时与最近发现的Orion X恒星种群相关联，这一事件塑造了我们今天观察到的气体的分布和运动学，尽管这不太可能是该地区唯一的主要反馈事件。我们认为，大多数YSO的动力学都带有反馈驱动的恒星形成历史记录的记忆，并且该建筑群中的大多数年轻恒星都是大规模触发的产物，它可以至少提高恒星形成速率，例如Orion A的头部（整体形状的灯丝）。我们的结果表明，反馈，压缩和触发过程在于Orion B中的Orion Nebula群集和NGC2023/2024的起源，从而广泛确认了Elmegreen＆Lada（1977）中提出的经典反馈驱动的场景。著名的年轻紧凑型簇的太空动作，$σ$ ORIONIS和NGC 1977，与这种情况一致。动量估计表明，需要几到几个超新星的能量来为我们在本文中测量的相干3D气体运动提供动力。
We present the first study of the 3D dynamics of the gas in the entire southern Orion cloud complex. We used the parallaxes and proper motions of YSOs from Gaia DR2 as a proxy for gas distance and proper motion, and the gas radial velocities from archival CO data, to compute the space motions of the different star-forming clouds in the complex, including subregions in Orion A, Orion B, and two outlying cometary clouds. From the analysis of the clouds' orbits in space and time, we find that they were closest about 6 Myr ago and are moving radially away from roughly the same region in space. This coherent 100-pc scale radial motion supports a scenario where the entire complex is reacting to a major feedback event, which we name the Orion-BB (big blast) event. This event, which we tentatively associate with the recently discovered Orion X stellar population, shaped the distribution and kinematics of the gas we observe today, although it is unlikely to have been the sole major feedback event in the region. We argue that the dynamics of most of the YSOs carry the memory of the feedback-driven star formation history in Orion and that the majority of the young stars in this complex are a product of large-scale triggering, which can raise the star formation rate by at least an order of magnitude, as for the head of Orion A (the Integral Shape Filament). Our results imply that a feedback, compression, and triggering process lies at the genesis of the Orion Nebula Cluster and NGC2023/2024 in Orion B, thus confirming broadly the classical feedback-driven scenario proposed in Elmegreen & Lada (1977). The space motions of the well-known young compact clusters, $σ$ Orionis and NGC 1977, are consistent with this scenario. A momentum estimate suggests that the energy of a few to several supernovae is needed to power the coherent 3D gas motion we measure in this paper.
