RUI: HII Region Evolution in Extreme Environments

AST-0206103De PreeHII区域随着观测技术的改进和亚角秒射频观测成为可能，已经缓慢地揭示了它们的性质。然而，这些存在于最大质量年轻恒星周围的电离气体，至少在它们形成和演化的早期阶段，是银河系中最不为人所知的天体之一。被称为超致密(UC)HII区的小型近亲HII区与经典教科书中描述的微秒级、光学薄的HII区非常不同。证据是明确的：UC HII区域不是简单的小HII区域，它们代表了一类独特的物体。克里斯托弗·德·普里博士的研究项目的目标是将最近和拟议中的观测与流体动力学模拟进行比较，以更全面地了解UC HII区域的性质，以及它们的形态、温度、运动学和演化告诉我们关于大质量恒星形成的早期阶段的信息。UC HII区域从未在这些小空间尺度上被成像和绘制光谱图。要研究的光源在光学上是不可观测的，在阿塔卡马大型毫米波阵列(ALMA)在未来十年投入使用之前，这些将是可用的最佳数据。这些新数据为约束UC HII区域演化的水动力模拟提供了最佳的比较数据。艾格尼丝·斯科特学院项目在让本科生女性参与天文学研究并为她们的研究生工作做好准备方面有着被证明是成功的记录，该项目将继续并加强这一努力，通过在两个主要的国家研究生项目(北卡罗来纳州立大学和哈佛大学)向科学家提供研究参与和接触。相关项目的早期数据已与一些调查人员非正式地分享，该项目将使现有数据和新数据免费可用。该奖项由美国国家科学基金会本科生研究计划(RUI)赞助。*

AST-0206103De PreeHII regions have revealed their nature slowly as observational techniques have improved and as subarcsecond radio frequency observations have become possible. Yet, these volumes of ionized gas that exist around the most massive young stars, at least in the early stages of their formation and evolution, are some of the least understood objects in the Galaxy. The diminutive cousins of HII regions called ultracompact (UC) HII regions are very different from the parsec-scale, optically-thin HII regions described in classic textbooks. The evidence is clear: UC HII regions are not simply small HII regions, they represent a unique class of object. The goal of Dr. Christopher De Pree's research project is to compare recent and proposed observations with hydrodynamic simulations to move toward a more complete understanding of the nature of UC HII regions and what their morphologies, temperatures, kinematics and evolution tell us about the earliest stages of massive star formation. UC HII regions have never been imaged and mapped spectroscopically on these small spatial scales. The sources to be studied are optically unobservable, and these will be the best data available until the Atacama Large Millimeter Array (ALMA) is dedicated in the coming decade. These new data provide the best comparison data to constrain hydrodynamic simulations of UC HII region evolution. The Agnes Scott College program has a proven record of success in involving undergraduate women in astronomical research and preparing them for graduate work, and this project would continue and strengthen that effort by providing research involvement and exposure to scientists at two premiere national graduate programs (North Carolina State University and Harvard University). Early data from related projects have been shared informally with a number of investigators, and this project would make existing data and new data freely available. This award is made under the auspices of the Research in Undergraduate Institutions (RUI) program at NSF.***