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: 1518263
• 负责人: Bahram Mobasher
• 金额: $ 8.69万
• 依托单位: University of California-Riverside
• 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 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1518263&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.

该小组将使用地面望远镜，配备有特殊用途的过滤器，以寻找宇宙中最遥远的星系。这些星系是第一个形成的星系，可能是导致宇宙中物质从中性到电离状态的根本转变的原因。这种状态的改变使年轻的宇宙沿着一条道路前进，这条道路导致了今天成熟宇宙中丰富的星系，恒星和行星。为研究所获得的数据将显示出丰富的信号强度模式，作为其电磁频率的函数。作为一项新的外展工作的一部分，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，并在信号的响度中给它们留下丰富的模式。这使得人类的耳朵能够“探测”到已知的最遥远的星系。MP3文件将被开发和发布沿着解释性材料。该项目的目的是调查早期宇宙何时以及如何被再电离，这是宇宙学中一个关键的未解决的问题。将采取分阶段的观察方法。在第一阶段，将获得窄带巡天的数据，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Lyman α发射星系的光度函数。该函数将产生约束的星系际介质（IGM）在这些红移的电离度。该团队开创了这种光度函数方法，首次使用它来显示IGM在红移6.5时主要是电离的。该团队的新工作将把第一个限制放在IGM的电离度上，甚至是更极端的红移。光谱学也将用于研究其他IGM性质。为研究所获得的光谱数据将展示信号强度随其电磁频率变化的丰富模式。作为一项新的外展工作的一部分，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，并在信号的响度中给它们留下丰富的模式。这使得人耳可以模仿摄谱仪。MP3文件将连同解释性材料沿着制作和发行。