Collaborative Research: Cosmology with CHIME

合作研究：与 CHIME 的宇宙学

• 批准号: 2006911
• 负责人: Laura Newburgh
• 金额: $ 28.32万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2006911&HistoricalAwards=false
• 关键词: Collaborative; Research; Cosmology; CHIME

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) will help understand dark energy by mapping out the distribution of matter throughout the Universe. One of the greatest mysteries in science is that the expansion of the Universe is currently accelerating, implying that a mysterious dark energy permeates the Universe and pushes on it. The discovery of dark energy resulted in a Nobel Prize, but its nature is no clearer today than it was 20 years ago. In fact, more recent measurements have led to less certainty, with different measurements of exactly how fast the Universe is expanding. CHIME is a new radio telescope designed to measure distant galaxies through the radio emission of neutral hydrogen gas that resides within them. In order to measure the hydrogen emission, other bright radio signals from our own galaxy and other sources must be removed. This foreground removal requires a precise understanding of the CHIME instrument itself. This project will measure the instrument, improve nuisance radio emission removal, and combine the CHIME measurements with galaxy catalogues to make a measurement of dark energy. The program will also develop education-oriented radio receivers that will be used in STEM programs at MIT, WVU and Yale. Radio receivers for education have been developed through a partnership between WVU and the Green Bank Observatory to teach teachers the digital signal processing techniques necessary to build a digital spectrometer.Analysis will be undertaken that cross-correlates 21cm maps from CHIME with optical galaxy survey data from eBOSS to measure the large-scale structure (LSS) of the Universe. CHIME is designed to measure neutral hydrogen associated with galaxies at redshifts from 0.8 to 2.5, producing constraints on dark energy over a critical redshift range that is difficult to probe statistically with optical galaxy surveys alone. To make this measurement bright foreground emission from our own galaxy and extragalactic sources must be removed, which places stringent requirements on instrument calibration. In this program the researchers will attempt to measure the expansion history through: (i) improved instrument beam modelling, (ii) demonstrated foreground removal techniques, and (iii) the measurement of large-scale structure with 21cm emission in cross-correlation with eBOSS optical galaxies.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.

加拿大氢强度测绘实验（CHIME）将通过绘制整个宇宙的物质分布来帮助了解暗能量。 科学中最大的谜团之一是宇宙目前正在加速膨胀，这意味着一种神秘的暗能量渗透到宇宙中并推动着它。 暗能量的发现获得了诺贝尔奖，但它的本质今天并不比 20 年前更清楚。 事实上，最近的测量结果导致了不确定性的降低，因为对宇宙膨胀速度的准确测量有不同的测量结果。 CHIME 是一款新型射电望远镜，旨在通过星系内部中性氢气的射电发射来测量遥远的星系。 为了测量氢的排放，必须去除来自我们自己的星系和其他来源的其他明亮的无线电信号。 这种前景去除需要对 CHIME 乐器本身有精确的了解。 该项目将测量仪器，改善无害无线电发射消除，并将 CHIME 测量与星系目录相结合以测量暗能量。 该计划还将开发面向教育的无线电接收器，用于麻省理工学院、西弗吉尼亚大学和耶鲁大学的 STEM 项目。西弗吉尼亚大学和绿岸天文台合作开发了用于教育的无线电接收器，向教师传授构建数字光谱仪所需的数字信号处理技术。将进行分析，将 CHIME 的 21 厘米地图与光学星系调查数据进行交叉关联eBOSS 测量宇宙的大尺度结构 (LSS)。 CHIME 旨在测量与红移为 0.8 至 2.5 的星系相关的中性氢，在临界红移范围内对暗能量产生限制，而仅通过光学星系巡天很难对暗能量进行统计探测。为了进行这种测量，必须去除来自我们自己的星系和河外源的明亮前景发射，这对仪器校准提出了严格的要求。 在此计划中，研究人员将尝试通过以下方式测量膨胀历史：(i) 改进的仪器光束建模，(ii) 演示前景去除技术，以及 (iii) 与 eBOSS 互相关的 21 厘米发射大型结构的测量该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。