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，天文学家已经知道分子云是星系形成恒星的“引擎”，但由于它们的复杂性，我们仍然缺乏对它们如何进化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，这种结构主要由致密但没有恒星的气体团块组成。PI将带领一组本科生研究人员对两个附近分子云的内部结构、物理条件和气体运动进行第一次大规模的测绘研究，利用各种分子线跃迁到中至高密度的微量气体，具有足够的角分辨率来探测细丝和嵌入的致密核心，恒星最终将在那里形成。该奖项将为天文学界提供宝贵的遗产数据集，同时为庞大而多样化的本科生群体提供独特的小组学习研究体验，并通过讲座和明星派对吸引公众。该团队将使用亚利桑那射电天文台12米望远镜（ARO 12米）绘制金牛座和Aquila裂谷分子云的地图，从多秒差距的细丝尺度到0.1秒差距以下的核心尺度。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，因此能够探测中高气体密度（HCN, H13CN， CS， SO, NH2D， c-C3H2和CH3OH）的互补线跃迁的观测将用于约束分子细丝和核心的共同进化。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，用于研究两个大的、附近的分子云中的中间和高密度分子气体，这将解决关于分子云中质量如何流动的基本问题，并有助于约束控制它们的最重要的物理过程。这些已解决的观测揭示的分子气体特性将影响我们对尚未解决的星系外恒星形成研究的理解。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

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.