Collaborative Research: First Light and Reionization with Lyman Alpha Galaxies

合作研究：莱曼阿尔法星系的第一束光和再电离

• 批准号: 1518057
• 负责人: James Rhoads
• 金额: $ 31.5万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1518057&HistoricalAwards=false
• 关键词: Collaborative; Research; First; Light; Reionization

The team will use ground-based telesopes, kitted out with special purpose filters, to hunt for the most distant galaxies in theUniverse. These galaxies were the first to form and are probably responsible for radically transforming the matter in the youngUniverse from a neutral to an ionized state. That state-altering transition sent the young Universe down a path that led to the rich panoply of galaxies, stars, and planets in today's mature Universe. The data acquired for the research will exhibit richpatterns in the strength of the signal as a function of its electromagnetic frequency. As part of a novel outreach effort, the team will sonify these data, that is, convert them to audible frequencies and imprint them with rich patterns in the loudness of the signal. This allows the human ear to "detect" the most distant galaxies known. MP3 files will be developed and released along with explanatory material.The aim of the project is to investigate when and how the early Universe became reionized, a key unsolved problem in cosmology. Astaged observational approach will be taken. In the first stage, data from narrow-band surveys will be acquired to find candidateLyman-alpha-emitting galaxies at redshifts of 7.7 and 8.8. In the second stage, spectroscopic follow-up of the candidates will be doneto confirm their high redshifts and form a luminosity function of Lyman-alpha-emitting galaxies. That function will yield constraints onthe degree of ionization of the intergalactic medium (IGM) at those redshifts. The team pioneered this luminosity-function approach, usingit to show for the first time that the IGM is largely ionized at a redshift of 6.5. The team's new work will place the first constrainson the degree of ionization of the IGM at even more extreme redshifts. The spectroscopy will also be used to study other IGMproperties. The spectroscopic data acquired for the research will exhibit rich patterns in the strength of the signal as a function of its electromagnetic frequency. As part of a novel outreach effort, the team will sonify these data, that is, convert them to audible frequencies and imprint them with rich patterns in the loudness of the signal. This allows the human ear to emulate a spectrograph. MP3 files will be developed and released along with explanatory material.

该团队将使用配备特殊用途过滤器的地面望远镜来寻找宇宙中最遥远的星系。这些星系是最先形成的，并且可能负责将年轻宇宙中的物质从中性状态彻底转变为电离状态。这种改变状态的转变使年轻的宇宙走上了一条道路，这条道路导致了今天成熟宇宙中丰富的星系、恒星和行星。研究获得的数据将呈现出信号强度随电磁频率变化的丰富模式。作为一项新颖的推广工作的一部分，该团队将对这些数据进行声音处理，即将它们转换为可听频率，并在信号响度中印上丰富的模式。这使得人耳能够“探测”已知最遥远的星系。 MP3 文件将与解释材料一起开发和发布。该项目的目的是调查早期宇宙何时以及如何重新电离，这是宇宙学中尚未解决的一个关键问题。将采取分阶段观察方法。在第一阶段，将获取窄带巡天数据，以寻找红移为 7.7 和 8.8 的候选莱曼 α 发射星系。在第二阶段，将对候选星系进行光谱跟踪，以确认它们的高红移并形成莱曼α发射星系的光度函数。该函数将对星系间介质（IGM）在这些红移处的电离程度产生限制。该团队首创了这种光度函数方法，利用它首次表明 IGM 在红移为 6.5 时大部分被电离。该团队的新工作将首次将 IGM 的电离程度限制在更极端的红移处。该光谱还将用于研究 IGM 的其他特性。研究获得的光谱数据将呈现丰富的信号强度模式，作为其电磁频率的函数。作为一项新颖的推广工作的一部分，该团队将对这些数据进行声音处理，即将它们转换为可听频率，并在信号响度中印上丰富的模式。这使得人耳可以模拟光谱仪。 MP3 文件将与解释材料一起开发和发布。