Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.
Monta Vista High School, 21840 McClellan Road, Cupertino, California 95014, United States.
J Phys Chem A. 2021 May 27;125(20):4267-4275. doi: 10.1021/acs.jpca.0c10983. Epub 2021 Apr 1.
Current theory and measurements establish the age of the universe as ca. 13.8 billion years. For the first several hundred million years of its existence, it was a dark, opaque void. After that, the hydrogen atoms comprising most of the "ordinary" matter began to condense and ionize, eventually forming the first stars that would illuminate the sky. Details of how these "primordial" stars formed have been widely debated, but remain elusive. A central issue in this process is the mechanism by which the primordial gas (mainly hydrogen and helium atoms) collected via the action of dark matter cooled and further accreted to fusion densities. Current models invoke collisional excitation of H molecular rotations and subsequent radiative rotational transitions allowed by the weak molecular quadrupole moment. In this work, we review the salient considerations and present some new ideas, based on recent spectroscopic observations of neutral H Rydberg electronic state emission in the mid-infrared region.
当前的理论和测量确立了宇宙的年龄约为 138 亿年。在其存在的最初几亿年里，它是一个黑暗、不透明的虚空。之后，构成大部分“普通”物质的氢原子开始凝聚和电离，最终形成了照亮天空的第一批恒星。这些“原始”恒星是如何形成的细节一直存在广泛争议，但仍难以捉摸。这个过程中的一个核心问题是原始气体（主要是氢和氦原子）通过暗物质的作用收集、冷却并进一步吸积到融合密度的机制。当前的模型通过弱分子四极矩允许的 H 分子旋转的碰撞激发和随后的辐射旋转跃迁来调用。在这项工作中，我们基于中性 H 里德伯电子态发射在中红外区域的最近光谱观测，回顾了突出的考虑因素并提出了一些新的想法。
