Unlocking the unexplored epoch of cosmic dawn with radio telescopes and advanced analysis techniques

利用射电望远镜和先进的分析技术解锁宇宙黎明的未探索时代

• 批准号: RGPIN-2018-04936
• 负责人: Liu, Adrian
• 金额: $ 2.4万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=657733
• 关键词: Unlocking; unexplored; epoch; cosmic; dawn

Cosmologists have now observed both the Universe today as well as its primordial conditions. However, the crucial epoch of Cosmic Dawn---the period when the first stars and galaxies illuminated our Universe---remains unobserved. As a result, we remain ignorant of how modern astronomical structures came to be. For instance, what was the nature of the first galaxies? Were they primarily large galaxies or a broader population of smaller ones? What role, if any, did the particle physics of neutrinos and (possibly) annihilating dark matter play in this era?******My research program unlocks the era of Cosmic Dawn to direct observations. We do so via 21cm tomography, where faint radio emission from neutral hydrogen atoms are used to make large scale maps of our Universe. These maps then provide a direct picture of how first-generation galaxies illuminated, ionized, and permanently altered our cosmos.******This Discovery Grant research program targets the opportunity to turn the long-term vision of 21cm cosmology into observational reality using data from the Hydrogen Epoch of Reionization Array (HERA), a novel low-frequency radio interferometer. The short-term activities to be undertaken in this grant period are to:******(1) Deliver a software pipeline for reducing raw HERA data into the first direct images of Cosmic Dawn and statistical quantities such as a power spectrum measurement.******(2) Analyze and interpret the resulting power spectra to determine the properties of first-generation galaxies, such as their typical mass, their clustering, and their emission properties. Interface with other cosmological probes (such as the Cosmic Microwave Background) to produce sharpened constraints on fundamental parameters such as the neutrino mass.******(3) Incorporate machine learning techniques to develop next-generation analysis techniques for 21cm cosmology. Move beyond power spectrum analyses by applying image-recognition techniques to images of Cosmic Dawn. Use machine-learning to aid in the design and optimization of next-generation telescopes.******This grant will provide training for undergraduates, graduate students, and postdoctoral fellows in the emerging field of 21cm cosmology. Their expertise and the analysis tools that are developed as part of this proposal will be made available to the large Canadian presence in 21cm cosmology, including CHIME, the Murchison Widefield Array, and the Square Kilometre Array.

宇宙学家现在既观察到了今天的宇宙，也观察到了它的原始状态。然而，宇宙黎明的关键时期--第一批恒星和星系照亮我们宇宙的时期--仍然没有被观测到。因此，我们仍然不知道现代天文结构是如何形成的。例如，第一个星系的性质是什么？它们主要是大星系还是更广泛的小星系？中微子和（可能）湮灭暗物质的粒子物理学在这个时代扮演了什么角色？我的研究计划开启了宇宙黎明的时代，以直接观察。我们通过21厘米层析成像来做到这一点，中性氢原子发出的微弱无线电辐射被用来绘制我们宇宙的大比例地图。然后，这些地图提供了第一代星系如何照亮，电离和永久改变我们宇宙的直接画面。这个发现补助金研究计划的目标是利用一种新型低频射电干涉仪氢时代再电离阵列（HERA）的数据，将21厘米宇宙学的长期愿景转化为观测现实。**（1）提供一个软件管道，将HERA原始数据简化为宇宙黎明的第一张直接图像和统计量，如功率谱测量。(2)分析和解释由此产生的功率谱，以确定第一代星系的属性，例如它们的典型质量，它们的集群和它们的发射特性。与其他宇宙学探测器（如宇宙微波背景）接口，以产生对中微子质量等基本参数的尖锐约束。(3)结合机器学习技术，为21厘米宇宙学开发下一代分析技术。通过将图像识别技术应用于宇宙黎明的图像，超越功率谱分析。使用机器学习来帮助设计和优化下一代望远镜。**该补助金将为本科生、研究生和博士后研究员提供21厘米宇宙学新兴领域的培训。他们的专业知识和分析工具，作为这一建议的一部分，将提供给加拿大在21厘米宇宙学的大型存在，包括CHIME，默奇森宽场阵列，和平方公里阵列。