Gas Excitation, Chemistry, and Dust in Super Star Clusters

巨大星团的形成是宇宙和银河系历史的重要组成部分。巨型星团包含着现存质量最大、最明亮的恒星。这些巨大的恒星在其内部迅速产生化学元素。来自恒星的强风和强烈的辐射场使这些元素丰富并分散到周围的云层中。受影响的云反过来又以一种尚不清楚的方式决定了星团的未来。阿塔卡马大型毫米/亚毫米阵列（ALMA）可以对分子光谱线的发射进行高保真成像。有了ALMA，现在可以观测到局部星系中的单个气体云。这项研究的目标是观察和模拟大质量恒星对年轻星团附近气体的影响。该项目为研究生和本科生提供培训，并将通过改进双语服务与当地社区建立更有效的联系。研究人员将使用ALMA来测量本地星系中最年轻的大质量星团附近分子云中气体和尘埃的特性。利用一氧化碳和其他分子的亚毫米谱线的高分辨率图像，形成超级星团的分子云的化学特征将被定义。这些云内的激发和化学的组合建模将使用代码CLOUDY来完成。目前计划在ALMA上观测到的分子线和尘埃的观测结果将进行分析、简化和建模。亚毫米光谱能量分布将用于估计星系团的尘埃含量和富集程度。运动学和激励结合在一起将允许内部云结构的三维视图。这个程序是在星团尺度上对气体的详细研究，目的是将星团如何与其出生云的气体和尘埃相互作用的形态学和动力学的综合图像放在一起。分析结果将被公布，数据产品，包括线立方及其衍生物，以及从建模中得到的线比网格，将提供给天文学界。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。

The formation of giant star clusters forms a key part of the history of the universe and our own Milky Way galaxy. Giant clusters contain the most massive and luminous stars in existence. These massive stars rapidly produce chemical elements in their interiors. Strong winds and intense radiation fields from the stars then enrich and disperse these elements into surrounding clouds. The affected clouds in turn determine the future of the cluster in ways that are as yet not well understood. The Atacama Large Millimeter/Submillimeter Array (ALMA) allows high-fidelity imaging of emission from spectral lines of molecules. With ALMA, it is now possible to observe individual gas clouds in local galaxies. The goals of this research are to observe and model the effects of massive stars on gas near young star clusters. The project provides for training of graduate and undergraduate students, and it will establish more effective links to the local community by improving bilingual outreach.The investigators will use ALMA to measure gas and dust properties in molecular clouds near the youngest massive clusters in local galaxies. Using high resolution images of submillimeter spectral lines of carbon monoxide and other molecules, chemical characteristics of molecular clouds forming super star clusters will be defined. Combined modeling of excitation and chemistry within these clouds will be done using the code, CLOUDY. Observations of molecular lines and dust currently scheduled to be observed at ALMA will be analyzed, reduced, and modeled. Submillimeter spectral energy distributions will be used to estimate the dust content and enrichment by the clusters. Kinematics and excitation together will allow a three-dimensional view of internal cloud structure. This program is the detailed study of gas on cluster scales, with the goal of putting together a comprehensive picture, morphological and dynamical, of how the cluster interacts with the gas and dust of its natal cloud. The results of the analyses will be published, and data products, including line cubes and their derivatives, and grids of line ratios from the modeling, will be made available to the astronomical community.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.