Revealing Gravitational Collapse in the Serpens G3–G6 Molecular Cloud Using Velocity Gradients
Revealing Gravitational Collapse in the Serpens G3–G6 Molecular Cloud Using Velocity Gradients
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DOI：
10.3847/1538-4357/abedb7
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发表时间：
2021-02
期刊：
影响因子：
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通讯作者：
Yue Hu;A. Lazarian;S. Stanimirović
中科院分区：
文献类型：
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作者：
Yue Hu;A. Lazarian;S. Stanimirović
在星星的形成中，湍流、磁场和自引力的相对作用是一个激烈争论的话题。我们提出了IRAM 30米望远镜观测的巨蛇座G3-G6分子云中的13 CO（1-0）发射，并应用于数据的一组统计方法。其中包括柱密度的概率密度函数和速度梯度技术。我们结合我们的数据与普朗克353 GHz的偏振尘埃发射观测和赫歇尔H2柱密度联合收割机。我们认为巨蛇座G3-G6南星团正在经历一次引力坍缩。我们的分析表明，引力坍缩发生在体积密度n ≥ 103 cm−3时。我们使用传统的Davis-Ehrasekhar-Fermi方法估计天空平面磁场强度约为120 μG，使用Lazarian等人提出的新技术估计为100 μG（）。我们发现巨蛇座G3-G6南星系团的总磁场能量明显超过动能和引力能。我们的结论是，引力坍缩可以成功地触发在超音速和亚Alfvénic云。
The relative role of turbulence, magnetic fields, and self-gravity in star formation is a subject of intensive debate. We present IRAM 30 m telescope observations of the 13CO (1–0) emission in the Serpens G3–G6 molecular cloud and apply to the data a set of statistical methods. These include the probability density functions of column density and the velocity gradients technique. We combine our data with the Planck 353 GHz polarized dust emission observations and Hershel H2 column density. We suggest that the Serpens G3–G6 south clump is undergoing a gravitational collapse. Our analysis reveals that the gravitational collapse happens at volume density n ≥ 103 cm−3. We estimate the plane-of-the-sky magnetic field strength to be approximately 120 μG using the traditional Davis–Chandrasekhar–Fermi method and 100 μG using a new technique proposed in Lazarian et al (). We find that the Serpens G3–G6 south clump’s total magnetic field energy significantly surpasses kinetic energy and gravitational energy. We conclude that the gravitational collapse could be successfully triggered in a supersonic and sub-Alfvénic cloud.