SIRIUS Project V. Formation of off-centre ionized bubbles associated with Orion Nebula Cluster
SIRIUS Project V. Formation of off-centre ionized bubbles associated with Orion Nebula Cluster
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天狼星项目 V. 与猎户座星云团相关的偏心电离气泡的形成
DOI：
10.1093/mnras/stac808
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发表时间：
2022
影响因子：
4.8
通讯作者：
Saitoh Takayuki R
中科院分区：
文献类型：
--
作者：
Fujii Michiko S;Hattori Kohei;Wang Long;Hirai Yutaka;Kumamoto Jun;Shimajiri Yoshito;Saitoh Takayuki R
在星星团中诞生的大质量恒星通过电离周围的气体来终止星星团的形成。这一过程被认为在包含大质量恒星的年轻星星星团中普遍存在。猎户座星云是一个很好的例子，它与一个正在形成的星星团有关，这个星团包括几颗大质量恒星（猎户座星云团，ONC）和一个2 pc大小的Hiiregion（电离泡），朝向观测者开放;然而，另一面仍然覆盖着致密的分子气体。盖亚卫星最近获得的天体测量数据揭示了该区域的恒星运动学。通过将这些数据与星星团形成模拟结果进行比较，我们证明了在ONC中心出生的大质量恒星是通过三体相遇被弹射出来的。此外，轨道分析显示，θ 2 Ori A是该区域的第二颗大质量星星，从ONC中心向观测者喷射，现在正在返回星团中心。这样的大质量恒星可以在稠密的分子云中形成一个洞，并有助于形成2-pc气泡。我们的研究结果表明，大质量恒星的动力学是必不可少的星星集群和Hiirregions的形成，并不总是由大质量恒星为中心。
Massive stars born in star clusters terminate star cluster formation by ionizing the surrounding gas. This process is considered to be prevalent in young star clusters containing massive stars. The Orion Nebula is an excellent example associated with a forming star cluster including several massive stars (the Orion Nebula Cluster, ONC) and a 2-pc-sized Hiiregion (ionized bubble) opening towards the observer; however, the other side is still covered with dense molecular gas. Recent astrometric data acquired by theGaiasatellite revealed the stellar kinematics in this region. By comparing these data with star cluster formation simulation results, we demonstrate that massive stars born in the ONC centre were ejected via three-body encounters. Further, orbit analysis indicates that θ2Ori A, the second massive star in this region, was ejected from the ONC centre towards the observer and is now returning to the cluster centre. Such ejected massive stars can form a hole in the dense molecular cloud and contribute to the formation of the 2-pc bubble. Our results demonstrate that the dynamics of massive stars are essential for the formation of star clusters and Hiiregions that are not always centred by massive stars.