Turbulence in Milky Way Star-forming Regions Traced by Young Stars and Gas
Turbulence in Milky Way Star-forming Regions Traced by Young Stars and Gas
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DOI：
10.3847/1538-4357/ac76bf
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发表时间：
2022-04
期刊：
影响因子：
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通讯作者：
T. Ha;Yuan Li;M. Kounkel;Siyao Xu;Hui Li;Yonggang Zheng
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文献类型：
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作者：
T. Ha;Yuan Li;M. Kounkel;Siyao Xu;Hui Li;Yonggang Zheng
星际介质（ISM）在巨大的尺度上处于不同阶段的湍流。在本文中，我们用不同的示踪剂研究了四个附近恒星形成区域的湍流：猎户座、蛇夫座、英仙座和金牛座。我们结合 APOGEE-2 和盖亚巡天来获得这些区域年轻恒星位置和速度的完整六维测量结果。恒星的速度结构函数（VSF）显示了湍流的普遍尺度。我们还从威斯康星州 H-Alpha 绘图仪获得了这四个区域的 Hα 气体运动学。与恒星相比，Hα 的 VSF 更加多样化。在最近发生超新星活动的区域，与文献中恒星和二氧化碳的 VSF 相比，它们表现出局部能量注入的特征和更高的振幅。 VSF 振幅的这种差异可以通过从超新星到 ISM 不同相的不同能量和动量传输来解释，从而导致 Hα 所追踪的暖电离相中出现更高水平的湍流。在近期没有超新星活动的区域，年轻恒星、Hα和CO的VSF大体一致，表明不同阶段之间存在良好耦合的湍流。在各个区域内，Hα 气体的较亮部分往往比低排放部分具有更高水平的湍流。我们的研究结果支持了银河系ISM的复杂图景，其中湍流可以在不同的尺度上驱动，并将能量不均匀地注入到不同的阶段。
The interstellar medium (ISM) is turbulent over vast scales and in various phases. In this paper, we study turbulence with different tracers in four nearby star-forming regions: Orion, Ophiuchus, Perseus, and Taurus. We combine the APOGEE-2 and Gaia surveys to obtain the full six-dimensional measurements of positions and velocities of young stars in these regions. The velocity structure functions (VSFs) of the stars show a universal scaling of turbulence. We also obtain Hα gas kinematics in these four regions from the Wisconsin H-Alpha Mapper. The VSFs of the Hα are more diverse compared to those of stars. In regions with recent supernova activities, they show characteristics of local energy injections and higher amplitudes compared to the VSFs of stars and of CO from the literature. Such difference in amplitude of the VSFs can be explained by the different energy and momentum transport from supernovae into different phases of the ISM, thus resulting in higher levels of turbulence in the warm ionized phase traced by Hα. In regions without recent supernova activities, the VSFs of young stars, Hα, and CO are generally consistent, indicating well-coupled turbulence between different phases. Within individual regions, the brighter parts of the Hα gas tend to have a higher level of turbulence than the low-emission parts. Our findings support a complex picture of the Milky Way ISM, where turbulence can be driven at different scales and inject energy unevenly into different phases.