Collaborative Research: Galactic Archaeology from Careful Modeling of Old Stars

合作研究：从对老恒星的仔细建模中进行银河考古学

• 批准号: 2206264
• 负责人: Alexander Ji
• 金额: $ 42.45万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2206264&HistoricalAwards=false
• 关键词: Collaborative; Research; Galactic; Archaeology; Careful

The history of star formation of the entire universe is hidden in the elements making up the oldest stars in our Milky Way Galaxy. Astronomers start to unravel that history by careful observations of metal-poor (old) red giant stars. Making further progress requires numerically modeling the observations. These investigators will enhance our understanding by creating more exact models. Their work is important because in the coming years, large observational spectroscopic surveys of our Milky Way Galaxy will push the distance and age frontiers of our knowledge. The investigators plan to help analyze enormous datasets using fast, physically motivated analysis tools. They will derive the stars’ current physical parameters and chemical compositions. Currently, most models use an approximation in stellar spectral analysis, called Local Thermodynamic Equilibrium (LTE). The investigators will use more realistic, but computationally expensive, non-LTE models. The investigators will significantly improve the accuracy of derived elemental abundances found in the metal-poor red giant stars, giving us a better understanding of the history of star formation. Additionally, the project will develop opportunities for under-represented and minority K-12 students from Florida schools to undertake research using the local teaching observatory and telescopes. It will also improve diversity in astronomy through equitable and inclusive mentoring of under-represented minority undergraduate students in summer research projects at the University of Chicago.This collaborative project between the University of Florida and the University of Chicago will enable fast, homogeneous derivation of non-LTE stellar parameters and chemical abundances by implementing non-LTE in full spectrum synthesis and using machine learning techniques to efficiently emulate the non-LTE grids. The results will be applied on industrial scales to large surveys of red giant stars covering both optical and infrared wavelengths. The project will produce user-friendly, publicly available codes that allow other astronomers to apply non-LTE analyses to their spectra.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.

在我们的银河系中构成最古老的恒星的轮胎宇宙，通过仔细观察金属折磨（旧）的巨星我们的乳白色的光谱将推动我们知识的距离和年龄段，以帮助使用快速的，富有性能的焦油的当前参数和Cal stigators使用更现实的，但昂贵的非LTE模型研究人员将显着改善金属贫困的红色巨星中发现的丰富ES，使我们更好地了解恒星形成的历史。 D望远镜。通过在全频谱合成中实现丰富的非LTE，并使用机器学习有效地模仿了非LTE网格。可用的代码允许其他天文学家对其光谱进行非LTE分析。该奖项反映了NSF'Stututory和Beanend值得通过使用讲述优点和更广泛影响的评估标准通过评估来支持的。

项目成果

Metal Mixing in the r-process Enhanced Ultrafaint Dwarf Galaxy Reticulum II*

r 过程中的金属混合增强型超微弱矮星系网状网 II*

• DOI: 10.3847/1538-3881/acad84
• 发表时间: 2023
• 期刊: The Astronomical Journal
• 作者: Ji, Alexander P.;Simon, Joshua D.;Roederer, Ian U.;Magg, Ekaterina;Frebel, Anna;Johnson, Christian I.;Klessen, Ralf S.;Magg, Mattis;Cescutti, Gabriele;Mateo, Mario
• 通讯作者: Mateo, Mario