Gas Excitation, Chemistry, and Dust in Super Star Clusters

巨型星星团的形成是宇宙和我们银河系历史的关键部分。巨大的星团包含了现存最大质量和最明亮的恒星。这些大质量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富集并分散到周围的云层中。受影响的云反过来又决定了集群的未来，其方式尚未得到很好的理解。阿塔卡马大型毫米/亚毫米阵列（阿尔马）允许对分子光谱线的发射进行高保真成像。有了阿尔马，现在有可能观测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，并将通过改进双语推广活动，与当地社区建立更有效的联系。调查人员将使用阿尔马来测量本地星系中最年轻的大质量星系团附近分子云中的气体和尘埃特性。利用一氧化碳和其他分子的亚毫米光谱线的高分辨率图像，将确定形成超级星星团的分子云的化学特征。将使用代码CLOUDY对这些云内的激发和化学进行组合建模。将对目前计划在阿尔马观测的分子线和尘埃进行分析、简化和建模。亚毫米光谱能量分布将用于估算尘埃含量和星团的富集程度。动力学和激发一起将允许内部云结构的三维视图。该计划是对星系团尺度上的气体进行详细研究，目的是将星系团如何与其纳塔尔云的气体和尘埃相互作用的形态学和动力学的全面图片放在一起。分析结果将被公布，数据产品，包括线立方体及其衍生物，以及从建模线比网格，将提供给天文学界。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.