arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1803.00566astro-ph.GAastro-ph.SR
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红外暗云周围[ CII ]辐射揭示的团簇形成的开端

The Inception of Star Cluster Formation Revealed by [CII] Emission Around an Infrared Dark Cloud

Thomas G. Bisbas, Jonathan C. Tan, Timea Csengeri, Benjamin Wu, Wanggi Lim, Paola Caselli, Rolf Guesten, Oliver Ricken, Denise Riquelme

摘要:

我们提出了SOFIA-upGREAT观测红外暗云(IRDC)G035.39-00.33的[CII]发射,旨在追踪其原子气体包层,从而测试这种云的起源模型。探测到[CII]发射的几个速度分量,追踪银河平面中距离很远的结构。我们发现一个主要的组成部分,可能与IRDC及其周围环境。这个最强的发射分量的速度与IRDC的$^{13}$ CO(2-1)发射的速度相似,但偏移了$\sim3\:{\rm km\:s}^{-1}$,并且具有更大的速度宽度$\sim9\:{\rm km\:s}^{-1}$。该成分的[CII]发射的空间分布也主要向IRDC的致密结构的一侧偏移。CII柱密度估计为$\sim10^{17}-10^{18}\,{\rm cm}^{-2}$量级。我们将这些结果与从巨分子云(GMC)碰撞形成的磁化致密气体细丝的数值模拟中的[CII]发射进行比较,发现类似的空间和运动学偏移。这些观测和对[CII]的建模进一步证明IRDC G035.39-00.33是由GMC-GMC碰撞过程形成的,因此这可能是启动恒星团簇形成的重要机制。

英文摘要:

We present SOFIA-upGREAT observations of [CII] emission of Infrared Dark Cloud (IRDC) G035.39-00.33, designed to trace its atomic gas envelope and thus test models of the origins of such clouds. Several velocity components of [CII] emission are detected, tracing structures that are at a wide range of distances in the Galactic plane. We find a main component that is likely associated with the IRDC and its immediate surroundings. This strongest emission component has a velocity similar to that of the $^{13}$CO(2-1) emission of the IRDC, but offset by $\sim3\:{\rm km\:s}^{-1}$ and with a larger velocity width of $\sim9\:{\rm km\:s}^{-1}$. The spatial distribution of the [CII] emission of this component is also offset predominantly to one side of the dense filamentary structure of the IRDC. The CII column density is estimated to be of the order of $\sim10^{17}-10^{18}\,{\rm cm}^{-2}$. We compare these results to the [CII] emission from numerical simulations of magnetized, dense gas filaments formed from giant molecular cloud (GMC) collisions, finding similar spatial and kinematic offsets. These observations and modeling of [CII] add further to the evidence that IRDC G035.39-00.33 has been formed by a process of GMC-GMC collision, which may thus be an important mechanism for initiating star cluster formation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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