Collaborative Research: WoU-MMA: The Benchmark Measurement of Quasar Spectroscopic Variability and Implications for Supermassive Black Hole Binaries and Changing-Look Quasars

合作研究：WoU-MMA：类星体光谱变异性的基准测量以及对超大质量黑洞双星和变化外观类星体的影响

• 批准号: 2205720
• 负责人: Michael Eracleous
• 金额: $ 23.43万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2205720&HistoricalAwards=false
• 关键词: Collaborative; Research; WoU; MMA; Benchmark

Most, if not all, reasonably massive galaxies host supermassive black holes in their centers, with masses of millions to billions of times the mass of the Sun. The most luminous non-exploding objects in the Universe, quasars are the result of gas falling onto these supermassive black holes and they can outshine all of the stars in their host galaxy. They are important because they appear to play a key role in shaping how galaxies came to look the way that they do today. However, because of their large cosmological distances, they appear as pinpricks of light on the sky and we cannot spatially separate the environment around the black hole to study its characteristics. Fortunately, quasars are intrinsically variable with frequent changes in brightness, making time-domain observations a powerful tool in revealing their central regions, akin to using a movie to tell a story instead of a single photograph. The research team at Vanderbilt and Penn State Universities will leverage these brightness changes and big data techniques to make the first measurement of how gas around supermassive black holes moves over a timescale of years to a decade. This will enable searches for exotic sources, like supermassive black holes in binary (SBHB) systems which have never been detected before, and changing-look quasars (CLQs) which turn on and off much faster than theory can explain. The investigators will also conduct a three-day data mining workshop for students in the Fisk-Vanderbilt Bridge Program and develop a series of introductory astronomy exercises using the popular Zooniverse interface.This project will constitute the benchmark measurement of multi-year quasar spectroscopic variability and apply it to searches for SBHBs and CLQs. This work will use a sample of approximately 5000 quasars from the Sloan Digital Sky Survey that have been observed spectroscopically more than once to measure the parameters of the broad H-beta line and their variability over times scales of 1-18 years. These will be used to define a statistical model for regular quasar variability, appropriate for many applications, including searches for SBHBs and CLQs. With this statistical tool the team will (a) compare the ensemble variability properties of SBHB candidates to a control sample for the first time, (b) test the nature of the best sub-pc separation SBHB candidates, (c) predict the necessary duration for SBHB monitoring campaigns to bear fruit, (d) constrain the masses that SBHB candidates can have, (e) determine for the first time whether CLQs represent extreme examples of normal quasar variability or a distinct phenomenon, and (f) define the CLQ class rigorously and quantitatively.This award addresses and advances the goals of the Windows on the Universe Big Idea.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.

大多数（即使不是全部）合理的星系在其中心拥有超级质量的黑洞，数百万到数十亿次太阳的质量。宇宙中最具发光的非爆炸物体是类星体，是气体落在这些超质量黑洞上的结果，它们可以超过宿主星系中的所有恒星。它们很重要，因为它们似乎在塑造星系如何以今天的方式塑造星系中起着关键作用。但是，由于它们的巨大宇宙学距离，它们出现在天空上的闪烁，我们无法在黑洞周围的环境上分离其特征。幸运的是，类星体在本质上是可变的，亮度频繁地变化，使时间域的观察成为揭示其中央区域的强大工具，类似于使用电影讲述故事而不是一张照片。范德比尔特（Vanderbilt）和宾夕法尼亚州立大学的研究团队将利用这些亮度变化和大数据技术来首先测量超级质量黑洞周围的天然气在数年到十年的时间内移动。这将使搜索异国情调的搜索，例如以前从未检测到的二进制（SBHB）系统中的超质量黑洞，以及更快地打开和关闭的更换外观的类星体（CLQ），它们比理论所能解释的要快得多。调查人员还将在Fisk-Vanderbilt Bridge计划中为学生进行为期三天的数据挖掘研讨会，并使用流行的Zooniverse界面开发一系列入门天文学练习。本项目将构成多年类测量的基准测量。这项工作将使用Sloan数字天空调查中大约5000种类星体的样本，这些样本在光谱上观察到了不止一次的光谱，以测量宽H-beta线的参数及其在1 - 18年的时间尺度上的变异性。这些将用于定义常规类星体可变性的统计模型，适用于许多应用程序，包括搜索SBHB和CLQ。 With this statistical tool the team will (a) compare the ensemble variability properties of SBHB candidates to a control sample for the first time, (b) test the nature of the best sub-pc separation SBHB candidates, (c) predict the necessary duration for SBHB monitoring campaigns to bear fruit, (d) constrain the masses that SBHB candidates can have, (e) determine for the first time whether CLQs represent extreme examples of normal Quasar的可变性或独特的现象，以及（F）严格和定量定义CLQ类。该奖项旨在解决宇宙大意上窗户的目标。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛影响的评估来评估Criteria的评估，并被视为值得通过评估的支持。