Fulfilling the Atomic Physics Needs for Spectral Diagnostics of Cosmic Chemical Evolution

理解宇宙中化学元素的演化对于理解星系的演化至关重要。 在背景类星体和伽马射线暴（GRB）余辉的背景下观测到的原子和离子的光谱（称为阻尼莱曼α（DLA）吸收体）是测量遥远星系中元素丰度的最灵敏工具。 该项目将产生从DLA吸收器中获得元素丰度所需的准确可靠的数据，使天文学家能够解释遥远星系的观测结果并测试化学演化模型。 该项目将培训研究生和本科生进行天体物理学研究，为高中生提供研究经验，并通过天文学外展活动吸引不同人群。研究团队将使用高级理论原子物理方法计算关键DLA和sub-DLA吸收体的光学跃迁的振子强度。 然后，该团队将通过将其与高质量天文光谱结合光电离建模进行基准测试来测试计算数据的可靠性。 通过对高红移类星体、伽玛暴和恒星形成星系的大尺度光谱观测进行精确解释，该项目将有助于推进我们对星系化学演化的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Understanding the evolution of chemical elements in the Universe is crucial for understanding the evolution of galaxies. Optical spectra of atoms and ions known as damped Lyman-alpha (DLA) absorbers observed against background quasars and gamma-ray burst (GRB) afterglows represent the most sensitive tools to measure elemental abundances in distant galaxies. This project will generate accurate and reliable data required to derive elemental abundances from DLA absorbers, allowing astronomers to interpret observations of distant galaxies and test models of chemical evolution. The project will train graduate and undergraduate students in astrophysical research, provide research experience to high school students, as well as engage a diverse population through astronomy outreach activities.Using high-level theoretical atomic physics methods, the research team will calculate oscillator strengths for optical transitions of key DLA and sub-DLA absorbers. The team will then test the reliability of the calculated data by benchmarking them against high-quality astronomical spectra in conjunction with photoionization modeling. By enabling accurate interpretation of large-scale spectroscopic observations of high-redshift quasars, GRBs, and star-forming galaxies, this project will help advance our understanding of the chemical evolution of galaxies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.