Collaborative Research: Bringing Primordial Microphysics out of the Dark Ages: Advanced Chemistry and Cooling Calculations for First Star Formation and Evolution

最近在我们对早期宇宙的理解上的重大进展可以归功于在数值流体力学、辐射传输和核合成模拟方面的令人印象深刻的发展，以及壮观的观测努力。然而，虽然人们承认微物理过程在第一批恒星的形成和演化中发挥着重要的作用，如果不是控制的话，但在化学和分子激发的处理方面一直缺乏改进。这个新的原子和分子计算程序，与早期恒星形成和演化的天体物理模型相结合，将把原始微物理的处理带到最先进的水平。各种氢和氚反应的显式量子力学计算将与当前的化学和冷却模型相结合，并添加到一系列早期恒星形成和演化图像的流体力学计算中。重点将放在非LTE分子水平的布居和由此产生的分子光谱上。然后，原始的化学/冷却网络将扩展到包括碳和氧等重元素。包括这种最先进的微物理在内的天体物理研究将调查镶嵌在光晕中的第三族恒星的光子逃逸分数，在化石电离氢区形成低质量第三族恒星的过程，以及第三族超新星的金属扩散行为。这项工作将通过将最先进的原子和分子计算应用于新问题来促进对原始和低金属丰度化学的理解。结果将被添加到与原始天体化学相关的反应和代码模块的网络可访问数据库中。该项目包括培训研究生，扩大目前的活动，让本科生和代表性不足的群体参加，加强天体化学研究的基础设施，并加强跨学科合作。此外，该技术和成果还适用于聚变能源、燃烧研究和大气化学等其他领域。

AST-0607524LeppRecent significant advances in our understanding of the early Universe can be attributed to impressive developments in numerical hydrodynamics, radiative transfer, and nucleosynthetic modeling, as well as spectacular observational efforts. However, while it is accepted that microphysical processes play an important, if not controlling, role in the formation and evolution of the first stars, improvements in the treatment of chemistry and molecular excitation have been lacking. This program of new atomic and molecular calculations, in conjunction with astrophysical modeling of early star formation and evolution, will bring the treatment of primordial microphysics to state-of-the-art. Explicit quantum-mechanical calculation of various hydrogen and deuterium reactions will be combined with current chemistry and cooling models and added into hydrodynamical calculations of a range of early star formation and evolution pictures. Emphasis will be placed on non-LTE molecular level populations and the resultant molecular spectra. The primordial chemical/cooling network will then be extended to include heavy elements such as carbon and oxygen. Astrophysical studies including this state-of-the-art microphysics will investigate the photon escape fraction from Population III stars embedded in halos, the formation of low-mass Population III stars in fossil ionized hydrogen regions, and metal dispersal behavior from Population III supernovae. This work will advance the understanding of primordial and low-metallicity chemistry by applying state-of-the-art atomic and molecular computations to new problems.Results will be added to a web-accessible database of reactions and code modules relevant to primordial astrochemistry. The project includes the training of graduate students, and extending current activities for the participation of undergraduate students and under-represented groups, enhancing the infrastructure of astrochemical research and strengthening interdisciplinary collaborations. In addition, the techniques and results are applicable to other areas such as fusion energy, combustion research, and atmospheric chemistry.