论文标题
小天狼星项目。 V.与猎户座星云群相关的中心离子气泡的形成
SIRIUS Project. V. Formation of off-center ionized bubbles associated with Orion Nebula Cluster
论文作者
论文摘要
明星簇中出生的巨大星星通过电离周围气体终止星团的形成。该过程被认为在包含巨大恒星的年轻恒星簇中很普遍。猎户座星云是与形成星形簇相关的一个很好的例子，其中包括几个巨大的恒星（猎户座星云群； ONC）和2-pc的大小H {\ sc ii}区域（离子化气泡）向观察者开放；但是，另一侧仍然被密集的分子气覆盖。 Gaia卫星获取的最新星体数据显示了该地区的恒星运动学。通过将这些数据与星簇形成模拟结果进行比较，我们证明了在ONC中心出生的巨大恒星通过三体遭遇驱逐出境。此外，轨道分析表明，$θ^2 $ ori A是该区域的第二个大型恒星，从ONC中心弹出向观察者，现在返回群集中心。这种喷射的巨星可以在密集的分子云中形成一个孔，并有助于2-PC气泡的形成。我们的结果表明，巨大恒星的动力学对于并非总是以巨大恒星为中心的恒星簇和H {\ sc ii}区域至关重要。
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 size H{\sc ii} region (ionized bubble) opening toward the observer; however, the other side is still covered with dense molecular gas. Recent astrometric data acquired by the Gaia satellite revealed the stellar kinematics in this region. By comparing this data with star cluster formation simulation results, we demonstrate that massive stars born in the ONC center were ejected via three-body encounters. Further, orbit analysis indicates that $θ^2$ Ori A, the second massive star in this region, was ejected from the ONC center toward the observer and is now returning to the cluster center. 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 H{\sc ii} regions that are not always centered by massive stars.
