Calibrating Quasars for Cosmology

校准宇宙学中的类星体

• 批准号: 1908716
• 负责人: Gordon Richards
• 金额: $ 10.22万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1908716&HistoricalAwards=false
• 关键词: Calibrating; Quasars; Cosmology

Cosmology can be described as the study of the history, future, structure, and geometry of the Universe and is a foundation of astronomical research. Astronomers' current best understanding of cosmology comes from using a certain type of exploding stars(supernovae) to "map" the Universe. However, a fundamental tenet of science is that results should be tested and confirmed with independent methods. This investigation thus seeks to determine if another type of astronomical object can be used to test current theories. These objects are black holes that lurk in the cores of all massive galaxies, some of which are actively "feeding" today and are called "quasars". Ultimately the goal is to attempt to determine if a sub-class of quasars can be used in the same way as supernovae to map the geometry of the universe. In this process a graduate student will be trained in modern data science methods and both the student and PI will support education and public outreach, through activities involving Drexel's Lynch Observatory, engaging with elementary and middle-school classrooms, and actively working to increase inclusion and diversity at both Drexel University and in the science community in general.This project has potential for advancing science because known quasars vastly outnumber the supernovae that are currently the foundation of cosmology and the quasars "live" longer in addition to having been discovered across cosmic time. What one might hope to learn from them would provide independent constraints on existing methods. This project will undertake a novel method for leveraging machine learning to improve and expand upon the use of quasars for cosmology. The work involves calibrating two relationships that can be applied to up to 500,000 known quasars and can be accomplished using existing public data from the Sloan Digital Sky Survey. The project is designed as a 1-year high-risk, high potential reward exploratory investigation that the proposing team is uniquely positioned to carry out. The results of this investigation will be broadly distributed, by making code and data products available not only through the science literature, but also common data-sharing platforms and outreach activities.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.

宇宙学可以被描述为研究宇宙的历史、未来、结构和几何，是天文学研究的基础。天文学家目前对宇宙学的最好理解来自于使用某种类型的爆炸恒星(超新星)来绘制宇宙地图。然而，科学的一个基本原则是，结果应该用独立的方法进行检验和确认。因此，这项调查试图确定是否可以使用另一种类型的天文物体来测试当前的理论。这些天体是潜伏在所有大质量星系核心中的黑洞，其中一些今天正在积极地“进食”，被称为“类星体”。最终的目标是试图确定类星体的一个子类是否可以像超新星一样被用来绘制宇宙的几何图形。在这个过程中，研究生将接受现代数据科学方法的培训，学生和PI都将支持教育和公共宣传，通过德雷克塞尔林奇天文台的活动，参与小学和中学课堂，并积极努力增加德雷克塞尔大学和整个科学界的包容性和多样性。这个项目具有推动科学发展的潜力，因为已知类星体的数量远远超过目前作为宇宙学基础的超新星，而且类星体被发现的时间更长。人们可能希望从他们那里学到的东西，将对现有方法提供独立的约束。这个项目将采用一种新的方法，利用机器学习来改进和扩大类星体在宇宙学中的使用。这项工作涉及校准两个关系，这两个关系可以应用于多达50万个已知类星体，并且可以使用斯隆数字天空调查的现有公共数据来完成。该项目被设计为一项为期一年的高风险、高潜在回报的探索性调查，提案团队处于独特的地位来执行。这项调查的结果将广泛传播，不仅通过科学文献提供代码和数据产品，还通过公共数据共享平台和外联活动提供代码和数据产品。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Exploring Changes in Quasar Spectral Energy Distributions across C iv Parameter Space

• DOI: 10.3847/1538-4357/ac6a5d
• 发表时间: 2022-06
• 期刊: The Astrophysical Journal
• 作者: A. Rivera;G. Richards;S. Gallagher;Trevor V. McCaffrey;A. Rankine;P. Hewett;O. Shemmer

Characterizing Quasar C iv Emission-line Measurements from Time-resolved Spectroscopy

• DOI: 10.3847/1538-4357/aba62c
• 发表时间: 2020-07
• 期刊: The Astrophysical Journal
• 作者: A. Rivera;G. Richards;P. Hewett;A. Rankine