Collaborative Research: Establishing the Physical Picture for Rest-optical Emission Lines in Star-forming Galaxies from Cosmic Noon to Cosmic Dawn

合作研究：建立从宇宙正午到宇宙黎明的恒星形成星系中的静止光学发射线的物理图像

• 批准号: 2307623
• 负责人: Ryan Sanders
• 金额: $ 20.84万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307623&HistoricalAwards=false
• 关键词: Collaborative; Research; Establishing; Physical; Picture

Astronomers aim to measure several fundamental properties of galaxies across cosmic time. These include the rate at which new stars are being born, the proportion of so-called heavy elements (e.g., oxygen) relative to hydrogen, and the nature of the radiation field to which the interstellar medium (ISM) is exposed (be it light from massive stars or from accretion onto a supermassive black hole). These key galaxy properties are commonly inferred from the pattern of spectral emission lines produced by the ionized ISM. However, it has been shown that the translation between the spectrum of a galaxy and the underlying physical conditions prevailing in that galaxy may be qualitatively different in galaxies observed within the first few billion years of cosmic time, relative to what is observed in the universe today. Shapley and Sanders will analyze data from several hundred galaxies, observed roughly 10 billion years ago when the universe was forming stars at its peak level, to establish this essential translation between galaxy spectral and physical properties. They will also build a publicly available software tool for the community for modeling the spectra of galaxies all the way back to cosmic dawn within the first billion years after the Big Bang. Shapley and Sanders will also engage in several efforts in public outreach, partnering with the WorldWide Telescope Ambassadors Program to develop interactive tours across the night sky on topics such as astronomical spectroscopy. They will incorporate these pedagogical materials into ongoing outreach efforts at each of their respective campuses.There are important questions regarding the translation of rest-optical emission line properties to physical ones (e.g., star-formation rate, gas-phase oxygen abundance, ionization parameter) in distant galaxies. The co-PIs have assembled the definitive sample of z=1.5-2.5 star-forming galaxies from the Keck MOSFIRE Deep Evolution Field (MOSDEF) survey. They will use this sample to establish the translation between galaxy emission-line and physical properties, and build and publicly release a software tool for robust modeling of the rest-optical emission-line spectra of distant galaxies all the way back to cosmic dawn (z6). The proposed products will provide a lasting legacy as we enter into a new era for near-IR spectroscopy with great observatories in space.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.

天文学家的目标是跨宇宙时间测量星系的几个基本性质。这些因素包括新恒星的诞生速度，所谓的重元素(例如，氧)相对于氢的比例，以及星际介质(ISM)暴露在其中的辐射场的性质(无论是来自大质量恒星的光，还是来自超大质量黑洞的吸积)。这些关键的星系属性通常是从电离的ISM产生的光谱发射线模式中推断出来的。然而，已经表明，在宇宙时间的最初几十亿年内观察到的星系，相对于今天在宇宙中观察到的星系，星系光谱与该星系中普遍存在的基本物理条件之间的转换可能存在本质上的不同。沙普利和桑德斯将分析数百个星系的数据，这些星系大约在100亿年前被观测到，当时宇宙正在形成恒星的巅峰水平，以建立星系光谱和物理性质之间的基本转换。他们还将为社区建立一个公开可用的软件工具，用于对宇宙大爆炸后第一个10亿年内宇宙黎明期间的星系光谱进行建模。沙普利和桑德斯还将在公共宣传方面做出几项努力，与全球望远镜大使计划合作，开发跨越夜空的天文光谱学等主题的互动旅游。他们将把这些教学材料纳入各自校园正在进行的推广工作中。关于将遥远星系中的静止光发射线属性转换为物理属性(例如，恒星形成率、气相氧丰度、电离参数)存在着重要的问题。联合PI已经组装了来自Keck MOSFIRE深部演化场(MOSDEF)调查的z=1.5-2.5恒星形成星系的最终样本。他们将使用这个样本来建立星系发射线和物理性质之间的转换，并建立并公开发布一个软件工具，用于对遥远星系的其余光学发射线光谱进行稳健的建模，直到宇宙黎明(Z6)。建议的产品将为我们进入近红外光谱分析的新时代提供持久的遗产，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。