论文标题

VLT-Flames狼蛛调查:两个doradus中两个巨大失控恒星的观察证据

The VLT-FLAMES Tarantula Survey: Observational evidence for two distinct populations of massive runaway stars in 30 Doradus

论文作者

Sana, H., Ramírez-Agudelo, O. H., Hénault-Brunet, V., Mahy, L., Almeida, L. A., de Koter, A., Bestenlehner, J. M., Evans, C. J., Langer, N., Schneider, F. R. N., Crowther, P. A., de Mink, S. E., Herrero, A., Lennon, D. J., Gieles, M., Apellániz, J. Maíz, Renzo, M., Sabbi, E., van Loon, J. Th., Vink, J. S.

论文摘要

已经提出了两种主要情况,即大量失控的恒星的起源 - 动态弹射或在第一个核心崩溃时从二进制中释放 - 但他们的相对贡献仍然在争论。 我们旨在在30个多拉德斯(Doradus)的两次大型光谱运动中进行大规模恒星,旨在在本地组中最庞大的活性星形成区域中O-Type失控人群的性质提供观察性约束。 我们使用VLT-Flames Tarantula调查获得的30个多拉德斯(Doradus)中的O-Type星人群的RV测量值和大规模二进制二进制监测来识别单元和二进制O型runaways。我们讨论它们的旋转特性,并定性地比较观察结果与射血情景的期望。 我们确定了23个单型O型失控对象,其中大部分在30多拉多斯的主要星形区域之外。我们发现在失控的人群中,快速旋转器(VSINI> 200 km/s)的不足,提供了30个多拉德斯田间快速旋转恒星过度的解释。考虑预计的旋转速率和视线速度(LOS)速度的注意事项明显不存在快速旋转(VSINI> 210k/ms),快速移动(V_ {LOS}> 60km/s)runaways,并暗示了两种不同的逃亡星星的存在:快速旋转的人群,但缓慢地移动了跑步仪,但缓慢地移动了跑步仪,并且是一个快速移动的跑步仪,并且是一个快速移动的跑步仪,并且是一个快速旋转的跑步仪,并提示了一个快速旋转的跑车。在我们的样本中,这些比率接近2:1。 我们认为,缓慢移动但迅速旋转的逃亡者是由二进制弹射导致的,同时迅速移动但缓慢旋转的逃亡可能是由于动态弹出而导致的。鉴于检测偏见会更强烈影响缓慢的人群,我们的结果表明,二进制进化场景主导了当前30个doradus的大量失控人群。

Two main scenarios have been proposed for origin of massive runaway stars -- dynamical ejection or release from a binary at the first core collapse -- but their relative contribution remains debated. Using two large spectroscopic campaigns towards massive stars in 30 Doradus, we aim to provide observational constraints on the properties of the O-type runaway population in the most massive active star-forming region in the Local group. We use RV measurements of the O-type star populations in 30 Doradus obtained by the VLT-FLAMES Tarantula Survey and the Tarantula Massive Binary Monitoring to identify single and binary O-type runaways. We discuss their rotational properties and qualitatively compare observations with expectations of ejection scenarios. We identify 23 single and one binary O-type runaway objects, most of them outside the main star-forming regions in 30 Doradus. We find an overabundance of rapid rotators (vsini > 200km/s) among the runaway population, providing an explanation of the overabundance of rapidly rotating stars in the 30 Doradus field. Considerations of the projected rotation rates and runaway line-of-sight (los) velocities reveal a conspicuous absence of rapidly rotating (vsini > 210k/ms), fast moving (v_{los} > 60km/s) runaways, and suggest the presence of two different populations of runaway stars: a population of rapidly-spinning but slowly moving runaways and a population of fast moving but slowly rotating ones. These are detected with a ratio close to 2:1 in our sample. We argue that slowly moving but rapidly spinning runaways result from binary ejections, while rapidly moving but slowly spinning runaways could result from dynamical ejections. Given that detection biases will more strongly impact the slow-moving population, our results suggest that the binary evolution scenario dominates the current massive runaway population in 30 Doradus.

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