RUI: Laboratory Studies of Early Universe Chemistry

早期宇宙结构形成的最新模型表明，在第一颗恒星形成的时期，氢和重氢分子是在1.01万开尔文之间崩塌原始气体云的主要冷却剂。最近探测到的再电离，以及高红移恒星的形成，强调了早期这些分子的产生和毁灭所起的关键作用。然而，对于特别重要的电荷交换和重排反应，公开的原子数据中存在重大的不确定性，甚至到数量级。这些不确定性转化为在这一关键时期对两种分子的相对丰度预测的主要不准确。这项研究包括一系列实验室调查，以测量宇宙物体形成的相关温度范围内相关反应的速率系数。来自圆柱形射频离子陷阱的新原子数据将指导理论计算，并将被引入星系前结构和第一恒星形成的模型，以研究其天体物理含义。这项研究将显著增强阿巴拉契亚州立大学的本科生学习经验，该大学的学生中有很大比例来自代表性不足的群体。使用它的新仪器和项目将极大地有利于不同群体的本科生和硕士研究生在校园内进行物理研究。这项研究还将加强最近在一些大学和政府实验室之间建立的合作。

AST-0406706CalamaiCurrent models for the creation of structure in the early Universe indicate that during the epoch of first star formation, the hydrogen and deuterated hydrogen molecules are the dominant coolants for collapsing primordial gas clouds at temperatures between ten thousand and one hundred Kelvin. The recent detection of reionization, and thus star formation, at high redshift, underscores the pivotal role played by the creation and destruction of these molecules at early times. However, significant uncertainties, even to orders of magnitude, exist in the published atomic data for the particularly important charge exchange and rearrangement reactions. These uncertainties translate into major inaccuracies in the predicted relative abundances of both molecules at this key epoch. This study comprises a series of laboratory investigations to measure the rate coefficients for the relevant reactions in the relevant temperature range for cosmological object formation. New atomic data from a cylindrical radio-frequency ion trap will guide theoretical calculations, and will be introduced into models of pregalactic structure and first star formation to investigate the astrophysical implications.This study will significantly enhance the undergraduate learning experience at the Appalachian State University, whose student body includes a high proportion from under-represented groups. The new apparatus and projects using it will greatly benefit the on-campus physics research opportunities for a diverse group of undergraduate majors and masters level students. This research will also enhance recently established collaborations amongst a number of universities and government laboratories.