Collaborative Research: A Better Measurement of the Primordial Helium Abundance

合作研究：更好地测量原始氦丰度

• 批准号: 2205958
• 负责人: Erik Aver
• 金额: $ 20.47万
• 依托单位: Gonzaga University
• 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=2205958&HistoricalAwards=false
• 关键词: Collaborative; Research; Better; Measurement; Primordial

Within five minutes after the Big Bang, during primordial nucleosynthesis, almost all of the helium in the universe was produced. The production of that primordial helium depends on the content and interactions of the universe at that time. This makes a precise measurement of the amount of primordial helium of fundamental importance for testing models of new physics. Using observations of more than 40 metal-poor dwarf galaxies, this collaboration between scientists at the University of Minnesota, Gonzaga University, and The Ohio State University, will determine the primordial helium abundance with unprecedented precision, providing a fundamental test of models of new physics beyond the standard model. This program will have broader impacts through training graduate students, engaging undergraduates in research, and inspiring public interest in science. The public outreach components of this program consist of continuing the Universe in the Park program in the state of Minnesota, the use of the Ohio State University Arne Slettebak Planetarium to reach economically disadvantaged (and minority-majority) urban schools in Columbus and many rural schools in Ohio, and enhanced participation in the Science in Action! program for elementary school students in the Spokane, WA area, targeting schools with the most underserved and disadvantaged populations. Building on several recent investments and breakthroughs, it is now possible to reduce the observational uncertainty on the primordial helium abundance to below 1%, translating to an uncertainty of approximately 3% on the number of neutrino flavors. The Multi-Object Double Spectrographs (MODS) on the Large Binocular Telescope (LBT) enable the simultaneous observation of multiple hydrogen and helium recombination lines necessary for high-fidelity measurements of nebular helium abundances. This program will combine LBT/MODS spectra of metal-poor galaxies with near-infrared spectra and use an improved, sophisticated analysis methodology to determine helium abundances of individual targets with uncertainties of approximately 2%. With new observations of more than 40 metal-poor galaxies, the team will measure a value for the primordial helium abundance with an uncertainty of approximately 0.5%. This project takes advantage of the recent discoveries of many extremely metal-poor galaxies, access to sensitive new instruments on large telescopes, and increasingly sophisticated abundance analysis methodologies. A higher precision measurement of the primordial helium abundance will provide a strong constraint on many proposed models extending the standard model.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.

在大爆炸后的五分钟内，在原始的核合成期间，产生了几乎所有宇宙中的氦气。原始氦气的产生取决于当时宇宙的内容和相互作用。这可以精确地测量对于测试新物理学模型的基本重要性原始氦气量。利用对40多个金属贫困矮星系的观察，明尼苏达大学，冈萨加大学和俄亥俄州立大学的科学家之间的这一合作将确定前所未有的精确的原始氦气丰度，从而提供了超出标准模型的新型物理学模型的基本测试。该计划将通过培训研究生，使大学生参与研究并激发公众对科学的兴趣产生更大的影响。该计划的公共外展组成部分包括在明尼苏达州继续宇宙，俄亥俄州立大学Arne Slettebak天文馆使用俄亥俄州立大学的使用，以在哥伦比亚省的经济劣势（和少数群体中的城市学校）以及俄亥俄州的许多农村学校中的许多农村学校，并加强了参与科学的行动！在华盛顿州斯波坎的小学生计划，目标是服务不足和处于弱势群体的学校。在最近的几项投资和突破性的基础上，现在有可能将原始氦气丰度的观察不确定性降低到1％以下，转化为中微子口味数量约为3％的不确定性。大型双目望远镜（LBT）上的多对象双光谱仪（MOD）使得可以同时观察多个氢和氦重组线，以进行纯净的氦气丰度的高保真测量。该程序将将金属贫困星系的LBT/MODS光谱与近红外光谱相结合，并使用改进的，复杂的分析方法来确定单个目标的氦气丰度，而不确定性约为2％。有了新的40多个金属贫困星系的新观察，该团队将测量原始氦气丰度的价值，不确定性约为0.5％。该项目利用了许多极为贫穷的星系的最新发现，在大型望远镜上访问敏感的新仪器以及越来越复杂的丰度分析方法。对原始氦气丰度的更高精确度量将对许多扩展标准模型的模型提供强大的限制。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛影响的评估审查标准来通过评估来获得支持的。