An Undergraduate Group Research Project: Large Scale Mapping of the Structure and Kinematics of Filaments and Cores in Nearby Molecular Clouds

自20世纪60年代以来，天文学家就已经知道分子云是形成星系的星星“引擎”，但由于它们的复杂性，我们仍然缺乏对它们如何演变最终形成小而密集的团块，然后形成恒星的完整理解。对于被称为“细丝”的较大分子结构来说尤其如此，这些结构由致密但无星的气体团簇主导。PI将带领一个本科生研究团队对两个附近的分子云的内部结构，物理条件和气体运动进行第一次大规模的映射研究，利用各种分子线跃迁以足够的角分辨率来探测细丝和嵌入的致密核心，最终形成恒星。该奖项将为天文学界带来一个有价值的遗留数据集，同时为大量不同的本科生群体提供独特的小组学习研究体验，该团队将使用亚利桑那州射电天文台12米望远镜（ARO 12米）从多秒差距的尺度下到亚秒差距的尺度绘制金牛座和天鹰座裂谷分子云。0.1秒差距的核心尺度。由于没有单一的示踪剂，可以同时探测这些不同的尺度和物理条件，一组互补的线转换能够探测中间到高气体密度（HCN，H13 CN，CS，SO，NH 2D，C-C3 H2和CH 3OH）的观察将被用来约束分子丝和核心的共同演变。该奖项的一个关键智力价值是为社区提供了一个遗留数据集，用于研究两个大型附近分子云中的中等和高密度分子气体，这将解决有关分子云中质量流动的基本问题，并有助于限制控制它们的最重要的物理过程。这些解析观测揭示的分子气体性质将影响我们对尚未解决的河外星星形成研究的理解。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Astronomers have known since the 1960s that molecular clouds are the star forming "engines" of galaxies, but because of their complexity, we still lack a complete understanding of how they evolve to eventually form small, dense clumps and then stars. This is especially true for larger molecular structures called "filaments", which are dominated by dense but starless gas clumps. The PI will lead a team of undergraduate researchers to conduct the first large-scale mapping study of the internal structure, physical conditions, and gas motions for two nearby molecular clouds utilizing a variety of molecular line transitions to trace gas at intermediate to high densities with sufficient angular resolution to probe filaments and the embedded dense cores where stars should eventually form. This award will result in a valuable legacy dataset for the astronomical community and simultaneously provide a unique group-learning research experience for a large and diverse group of undergraduates, as well as engaging the public through lectures and star parties.The team will use the Arizona Radio Observatory 12m telescope (ARO 12m) to map the Taurus and Aquila Rift molecular clouds from multi-parsec filamentary scales down to sub-0.1 parsec core scales. Since there is no single tracer that can simultaneously probe these various scales and physical conditions, observations of a complementary set of line transitions capable of probing intermediate to high gas densities (HCN, H13CN, CS, SO, NH2D, c-C3H2 and CH3OH) will be used to constrain the co-evolution of molecular filaments and cores. A key intellectual merit of this award is in providing a legacy dataset to the community for studies of intermediate and high-density molecular gas in two large, nearby molecular clouds that will address fundamental questions about how mass flows within molecular clouds and help constrain the most important physical processes controlling them. The molecular gas properties revealed by these resolved observations will impact our understanding of unresolved extragalactic studies of star formation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.