Collaborative Research: Chemistry and Structure Formation at High Redshift

这是与Phillip Stancil博士（佐治亚大学，AST0087172）和Alexander Dalgarno博士（哈佛大学，AST0088213）的合作研究项目。这个项目将建立模型来研究第一批宇宙物体的形成。这些模型将描述早期宇宙中由原始气体形成的第一批束缚物体的历史。它们将包括随时间变化的非平衡化学、原子和分子水平种群的耦合演化，以及由于原始气体中的化学反应而产生的分子的非平衡旋转振动水平种群。这些模型可以用来建议从太空中观察早期宇宙红外结构的策略。这个项目将使用天体物理模型来研究第一个宇宙物体的形成。这些模型将计算与时间相关的非平衡化学、原子和分子水平的种群、热和流体动力学历史的耦合演化，这些历史是由原始气体形成的第一个束缚物体。这将是第一次尝试如此广泛的、耦合的进化模型。此外，本项目将研究由化学反应引起的原始分子的显式非平衡旋转振动能级居群，从而改进分子冷却的测定和原始云发射光谱的预测。发射光谱将被用来建议用下一代红外太空望远镜观察这些物体的最有可能的方式。所需的原子和分子数据以及衍生的冷却功能将被汇编并发布在万维网上。无法获得的数据，主要涉及旋转振动特定状态的分子碰撞，将使用已建立的量子力学技术进行计算。对原始气体的研究将扩展到在金属丰度增加和辐射场条件下的原星系和原恒星形成，直到星族II时代的开始。这些研究将与NGST、SIRTF、FIRST和Astro-F以及地面望远镜对未来天基观测的解释和规划有关。本项目由美国国家科学基金会星系外天文学和宇宙学项目（AST/EXC）资助

AST-0087348Stephen LeppThis is a collaborative research project with Drs Phillip Stancil, (the University of Georga, AST0087172), and Alexander Dalgarno, (Harvard University, AST0088213). This program will construct models to investigate the formation of the first cosmological objects. These models will describe the history of the first bound objects to form from the primordial gas in the early universe. They will include the coupled evolution of the time-dependent, nonequilibrium chemical, atomic and molecular level populations as well as the nonequilibrium rovibrational level populations of the molecules with contributions due to chemical reactions in the primordial gas. The models can be used to suggest strategies for observing structures in the early universe in the Infrared from space.This program will use astrophysical modeling to investigate the formation of the first cosmological objects. These models will compute the coupled evolution of the time-dependent nonequilibrium chemical, atomic and molecular level population, thermal, and hydrodynamic history of the first bound objects to form from the primordial gas. This will be the first time such extensive, coupled evolution models have been attempted. In addition, this project will investigate the explicit nonequilibrium rovibrational level populations of the primordial molecules with contributions due to chemical reactions, resulting in an improved determination of molecular cooling and the prediction of the emission spectra of primordial clouds. The emission spectra will be used to suggest the most likely ways these objects may be observed with the next generation of infrared space telescopes. The needed atomic and molecular data and derived cooling functions will be assembled and posted on the World Wide Web. The data that is not available, primarily involving rovibrational state-specific molecular collisions, will be computed with established quantum-mechanical techniques. The studies of the primordial gas will be extended to follow protogalaxy and protostar formation under increasing metallicity and radiation field conditions to the beginning of the era of Population II. These studies will be relevant to the interpretation and planning of future space-based observations with NGST, SIRTF, FIRST, and Astro-F and ground-based telescopes. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC).***