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

第一个光源形成于宇宙大爆炸后几亿年，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指定为核心科学目标。该项目将通过对最大望远镜收集的天文数据应用新方法，获得这个时代的新约束和第一个光源。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的研究，并吸引来自两个西班牙裔服务机构的本科生从事前沿天文学研究。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。高z类星体新的大型统计样本的吸收光谱具有巨大的未开发潜力。这个项目将研究Ly-alpha的统计特性；z ~ 6类星体光谱中的吸收。通过利用最近类星体数量的五倍增长，档案数据，新的方法和模拟，该项目将能够精确测量数百个类星体的光谱。该项目将：1)以远远超过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间介质的热量，为了解源（星系、AGN、Pop）提供新的见解。(3)恒星)再电离宇宙；(4)测量类星体寿命的分布；(5)对最近发现的年轻类星体的统计样本进行光谱表征。总体目标是将星系间介质的定量研究提升到与其他精确的宇宙学测量相同的坚实方法和统计基础上。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知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.