Intergalactic Archaeology: Decoding the Relics of Reionization in the Intergalactic Medium

星际考古学：解码星际介质中再电离的遗迹

• 批准号: 1816006
• 负责人: Joseph Hennawi
• 金额: $ 48.24万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1816006&HistoricalAwards=false
• 关键词: Intergalactic; Archaeology; Decoding; Relics; Reionization

The first sources of light formed several hundred million years after the Big Bang, ending what astronomers refer to as the cosmic dark ages. In the 2010 Decadal Survey, the US astronomy community designated the study of this epoch as a core science objective. This project will obtain new constraints on this epoch and the first sources of light by applying novel methods to astronomical data collected with the largest telescopes. These data will be compared to state-of-the-art supercomputer models to yield new insights into cosmic history. This project will support the research of a PhD student, partially support a postdoctoral scholar, and engage undergraduates from two hispanic serving institutions in cutting edge astronomical research. Determining exactly how and when reionization occurred are among the most important open questions in cosmology. Absorption spectroscopy of new large statistical samples of high-z quasars has tremendous untapped potential. This project will study the statistical properties of Ly-alpha; absorption in the spectra of z ~ 6 quasars. By leveraging the recent fivefold increase in the number of such quasars, archival data, new methodologies and simulations, this project will enable precise measurements of hundreds of quasar spectra. This project will: 1) reconstruct the reionization history at a precision that far surpasses existing methods, 2) measure the ionizing photon output from galaxies up to the end stages of reionization, 3) measure the amount of heat that was injected into the intergalactic medium by reionization, providing new insights into what sources (galaxies, AGN, Pop. III stars) re-ionized the Universe, 4) measure the distribution of quasar lifetimes, 5) spectroscopically characterize a statistical sample of recently discovered young quasars. The overarching goal is to elevate quantitative study of the intergalactic medium to be on the same solid methodological and statistical footing as other precision cosmological measurements.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.

第一个光源在大爆炸后数亿年形成，结束了天文学家所说的宇宙黑暗时代。 在2010年的十年调查中，美国天文学界将这一时期的研究定为核心科学目标。该项目将通过对用最大的望远镜收集的天文数据应用新的方法来获得对这个时代和第一光源的新限制。这些数据将与最先进的超级计算机模型进行比较，以产生对宇宙历史的新见解。该项目将支持一名博士生的研究，部分支持一名博士后学者，并吸引来自两个西班牙裔服务机构的本科生参与尖端天文学研究。确定再电离是如何以及何时发生的是宇宙学中最重要的未决问题之一。新的大统计样本的高z类星体的吸收光谱具有巨大的未开发的潜力。 本项目将研究z ~ 6类星体光谱中Ly-alpha吸收的统计性质。通过利用最近此类类星体数量增加五倍，档案数据，新方法和模拟，该项目将能够精确测量数百个类星体光谱。 该项目将：1）以远超现有方法的精度重建再电离历史，2）测量从星系到再电离结束阶段的电离光子输出，3）测量通过再电离注入星系际介质的热量，提供关于什么来源的新见解。（星系，活动星系核，第三类恒星）重新电离宇宙，4）测量类星体寿命的分布，5）光谱表征最近发现的年轻类星体的统计样本。总体目标是将星系际介质的定量研究提升到与其他精密宇宙学测量相同的坚实的方法学和统计学基础上。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

项目成果

Forecasting constraints on the mean free path of ionizing photons at z ≥ 5.4 from the Lyman-α forest flux autocorrelation function

根据 Lyman-α 森林通量自相关函数预测 z ≤ 5.4 处电离光子平均自由程的约束

• DOI: 10.1093/mnras/stad701
• 发表时间: 2023
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Wolfson, Molly;Hennawi, Joseph F.;Davies, Frederick B.;Oñorbe, Jose
• 通讯作者: Oñorbe, Jose

A Significantly Neutral Intergalactic Medium Around the Luminous z = 7 Quasar J0252–0503

• DOI: 10.3847/1538-4357/ab8c45
• 发表时间: 2020-04
• 期刊: The Astrophysical Journal
• 作者: Feige Wang;F. Davies;Jinyi Yang;J. Hennawi;Xiaohui Fan;A. Barth;Linhua Jiang;Xue-bing Wu

Evidence for Low Radiative Efficiency or Highly Obscured Growth of z > 7 Quasars

• DOI: 10.3847/2041-8213/ab42e3
• 发表时间: 2019-06
• 期刊: The Astrophysical Journal Letters
• 作者: F. Davies;J. Hennawi;A. Eilers