CAREER: Charting the Cosmic Dawn with Next Generation 21cm Arrays

事业：利用下一代 21 厘米阵列绘制宇宙黎明图

• 批准号: 2144995
• 负责人: Daniel Jacobs
• 金额: $ 99.34万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144995&HistoricalAwards=false
• 关键词: CAREER; Charting; Cosmic; Dawn; Next

Astronomers want to observe the Cosmic Dawn, when the first stars and galaxies formed. These observations would resolve many open questions about how galaxies came to be, but owing to the extreme distance, the time period has yet to be observed. Principal Investigator (PI) Jacobs and his team are working on instruments to observe the redshifted 21 cm radio signal emitted from hydrogen gas during the Cosmic Dawn. The low frequency radio signals are very faint as not only are the galaxies far away, but they are obscured by foreground galaxies in the nearby universe. PI Jacobs and his team will develop advanced instrument calibration tools and techniques for two 21cm cosmology instruments currently under construction, the Hydrogen Epoch of Reionization Array (HERA) and the Owens Valley Long Wavelength Array (OVRO-LWA). To broaden participation the PI will continue to mentor and provide stipends for students in both the Research Experience for Non-Traditional Undergraduates (RENTU) program and for his graduate students who are leading contributions to the Completely Hackable Amateur Radio Telescope (CHART) program. The graduate students provide kits and expert guidance to high school students and teachers so that they can build a radio telescope and observe hydrogen gas in the Milky Way.The systematic noise floor improvements will be addressed with drones, internal calibration sources, and laboratory measurements combined with advanced data analysis pipelines. The HERA power spectrum measurements will rule out exotic models and provide new constraints on canonical models of the first stars and galaxies. The PI will lead an OVRO-LWA cosmology program which aims to determine hydrogen 21 cm limits at redshifts 18 through 25 while also demonstrating techniques applicable on other instruments.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.

天文学家想要观测宇宙黎明，也就是第一批恒星和星系形成的时候。这些观测将解决许多关于星系是如何形成的悬而未决的问题，但由于距离极远，这个时间段尚未被观测到。首席研究员 (PI) Jacobs 和他的团队正在研制仪器来观测宇宙黎明期间氢气发出的红移 21 厘米无线电信号。低频射电信号非常微弱，因为不仅星系距离很远，而且它们还被附近宇宙中的前景星系遮挡。 PI Jacobs 和他的团队将为目前正在建造的两台 21 厘米宇宙学仪器、氢时代再电离阵列 (HERA) 和欧文斯谷长波长阵列 (OVRO-LWA) 开发先进的仪器校准工具和技术。为了扩大参与范围，PI 将继续为非传统本科生研究经验 (RENTU) 项目的学生和为完全可破解业余射电望远镜 (CHART) 项目做出贡献的研究生提供指导和津贴。研究生为高中生和教师提供套件和专家指导，以便他们能够建造射电望远镜并观测银河系中的氢气。系统的本底噪声改善将通过无人机、内部校准源和实验室测量相结合来解决具有先进的数据分析管道。 HERA 功率谱测量将排除奇异模型，并为第一批恒星和星系的规范模型提供新的约束。 PI 将领导一个 OVRO-LWA 宇宙学项目，该项目旨在确定红移 18 至 25 处的氢 21 厘米极限，同时展示适用于其他仪器的技术。该奖项反映了 NSF 的法定使命，并通过使用基金会的评估进行评估，被认为值得支持。智力价值和更广泛的影响审查标准。