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

了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)余辉中观察到的原子和离子的光学光谱，即被称为阻尼莱曼-阿尔法(DLA)的吸收体，是测量遥远星系中元素丰度的最敏感工具。该项目将产生准确和可靠的数据，以从DLA吸收体获得元素丰度，使天文学家能够解释对遥远星系的观测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研究，为高中生提供研究经验，并通过天文学推广活动吸引不同的人群。研究团队将使用高级理论原子物理方法，计算关键的DLA和亚DLA吸收体光跃迁的振子强度。然后，该团队将通过将计算数据与高质量的天文光谱进行基准比较，并结合光致电离建模来测试计算数据的可靠性。通过准确解释高红移类星体、伽玛暴和恒星形成星系的大规模光谱观测，该项目将有助于增进我们对星系化学演化的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力优势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.