Collaborative Research: Establishing the foundations of black hole mass measurements of AGN across cosmic time

超大质量黑洞是宇宙中最大的黑洞，其质量是太阳的数百万到数十亿倍。天文学的一个主要主题是了解这些黑洞是如何形成巨大质量的。这个项目将通过对类星体的观测研究来研究黑洞的生长，类星体是一种快速生长的超大质量黑洞。通过一种名为“回声映射”的方法，研究人员将确定类星体黑洞周围的气体流动方式，并测量黑洞的质量。这项工作将使用他们团队开发的新的数据分析工具和软件，这将使测量黑洞质量的精度比以前的方法更高。他们还将分析早期观测项目的数据，以便收集大量类星体和精确的黑洞质量测量数据。他们将利用这些结果开发改进的方法来估计宇宙中最遥远的类星体中黑洞的质量。这项工作将为研究宇宙历史上的黑洞生长提供一个重要的新基础。研究人员将与天文学专业的本科生合作，重点进行研究。他们将指导和建议考虑继续读研的学生，并将为“加州桥”项目的学生提供暑期研究机会。了解超大质量黑洞在宇宙时间内的生长和演化是天文学的中心主题。非常遥远的黑洞只有在它们通过从周围吸积物质并像类星体一样发出明亮的光芒而活跃地生长时才能被识别和研究。测量类星体中黑洞的质量是理解黑洞如何生长和影响其环境的关键。“回声映射”技术是研究类星体物理性质和黑洞质量的最佳工具之一。这种方法利用类星体光线随时间的变化来绘制黑洞周围气体的分布和运动。该项目的目标是通过结合新的观测和开发新的数据分析方法来推进类星体回波测绘科学。研究人员将利用几架望远镜获得新的回波测绘数据，并利用这些数据绘制黑洞周围气体的分布图。他们将应用我们团队开发的新的数据分析方法，在物理框架中解释回声映射数据，从而能够直接确定黑洞的质量。最后，他们将对早期工作中所有可用的回波测绘数据进行统一的重新分析，并利用结果推导出遥远类星体中黑洞质量的改进校准。这项工作将为研究宇宙历史上的黑洞生长提供一个严谨的新基础。研究人员将与天文学专业的本科生合作，重点进行研究。他们将指导和建议考虑继续读研的学生，并将为“加州桥”项目的学生提供暑期研究机会。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Part 1Supermassive black holes are the largest black holes in the universe, ranging from millions to billions of times the mass of the Sun. A major theme in astronomy is understanding how these black holes grew to their enormous masses. This project will investigate the growth of black holes by carrying out observational studies of quasars, which are supermassive black holes that are growing rapidly. Using a method called "echo mapping", the investigators will determine how gas flows around the black holes in quasars and measure the masses of the black holes. This work will use new data analysis tools and software developed by their team that will make it possible to measure the black hole masses with higher accuracy than earlier methods. They will also analyze data from earlier observing projects in order to assemble a large collection of quasars with accurate black hole mass measurements. They will use these results to develop improved methods to estimate the masses of black holes in the most distant quasars in the universe. This work will provide an important new foundation for studies of black hole growth across the history of the cosmos. The investigators will work with undergraduate astronomy majors, focusing on conducting research. They will mentor and advise students considering going on to graduate school, and will provide summer research opportunities to students in the "Cal-Bridge" program.Part 2Understanding the growth and evolution of supermassive black holes across cosmic time is a central theme in astronomy. Very distant black holes can only be identified and studied when they are actively growing by accreting matter from their surroundings and shining brightly as quasars. Measuring the masses of the black holes in quasars is a key to understanding how black holes grow and influence their environments. The technique of "echo mapping" is one of the best tools to study the physical properties and black hole masses of quasars. This method uses the variations over time in a quasar's light to map out the distribution and motion of gas around the black hole. The goal of this project is to advance the science of quasar echo mapping through a combination of new observations and the development of new data analysis methods. The investigators will acquire new echo mapping data using several telescopes, and use the data to map the distribution of gas around the black holes. They will apply new data analysis methods developed by our team to interpret echo mapping data in a physical framework that will enable direct determination of the masses of black holes. Finally, they will carry out a uniform re-analysis of all available echo mapping data from earlier work, and use the results to derive an improved calibration of the black hole masses in distant quasars. This work will provide a rigorous new foundation for investigations of black hole growth across the history of the universe. The investigators will work with undergraduate astronomy majors, focusing on conducting research. They will mentor and advise students considering going on to graduate school, and will provide summer research opportunities to students in the "Cal-Bridge" program.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.