The APOGEE-2 Survey of the Orion Star-forming Complex. II. Six-dimensional Structure
The APOGEE-2 Survey of the Orion Star-forming Complex. II. Six-dimensional Structure
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DOI：
10.3847/1538-3881/aad1f1
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发表时间：
2018-05
期刊：
影响因子：
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通讯作者：
M. Kounkel;K. Covey;Genaro Su'arez;C. Rom'an-Z'uniga;Jesús Hernández;K. Stassun;Karl O. Jaehnig
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文献类型：
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作者：
M. Kounkel;K. Covey;Genaro Su'arez;C. Rom'an-Z'uniga;Jesús Hernández;K. Stassun;Karl O. Jaehnig
我们提出了一种分析的光谱和天体测量数据来自远地点-2和Gaia DR2，以确定结构指向猎户座复合体。通过将层次聚类算法应用于六维恒星数据，我们识别了年龄从1到12 Myr的年轻恒星对象的空间和/或运动学上不同的组。我们还研究了猎户座复合体内的恒星形成历史，并确定了特殊的亚星系团。用这种方法，我们重建了目前基本上没有分子气体的地区的较老的种群，如猎户座C(包括σOrI星团)和猎户座D(追踪OriOB1a、OB1b和猎户座X的种群)。我们报告了建筑群内群体的距离、运动学和年龄。猎户座D集团正在进行扩张。另一方面，猎户座B仍处于收缩过程中。在λOri中，自行与超新星爆炸引起的径向膨胀是一致的；从膨胀中追溯的年龄超过了在该区域外边缘附近形成的最年轻恒星的年龄，当它们从星团中心到目前位置的一半时，它们的形成就会被触发。我们还比较了Gaia DR2得到的视差和自行解，以及由甚长基线阵列得到的恒星形成区的解。
We present an analysis of spectroscopic and astrometric data from APOGEE-2 and Gaia DR2 to identify structures toward the Orion Complex. By applying a hierarchical clustering algorithm to the six-dimensional stellar data, we identify spatially and/or kinematically distinct groups of young stellar objects with ages ranging from 1 to 12 Myr. We also investigate the star-forming history within the Orion Complex and identify peculiar subclusters. With this method we reconstruct the older populations in the regions that are currently largely devoid of molecular gas, such as Orion C (which includes the σ Ori cluster) and Orion D (the population that traces Ori OB1a, OB1b, and Orion X). We report on the distances, kinematics, and ages of the groups within the Complex. The Orion D group is in the process of expanding. On the other hand, Orion B is still in the process of contraction. In λ Ori the proper motions are consistent with a radial expansion due to an explosion from a supernova; the traceback age from the expansion exceeds the age of the youngest stars formed near the outer edges of the region, and their formation would have been triggered when they were halfway from the cluster center to their current positions. We also present a comparison between the parallax and proper-motion solutions obtained by Gaia DR2 and those obtained toward star-forming regions by the Very Long Baseline Array.