A Comprehensive Study of AGN Optical Variability from Minute to Decade Time Scales

该项目将全面研究活跃吸积物质的超大质量黑洞发出的辐射变化。几乎所有星系的中心都有一个超大质量黑洞，它们的活动星系核（AGN）释放出巨大的能量，可以超过星系中所有恒星的能量。AGN辐射是随时间变化的，这种变化是随机的，这是AGN吸积物理的重要编码。该团队将分析来自两个调查的数据集：超新星全天自动调查（ASAS-SN）和凌日系外行星调查卫星（TESS）。合并的数据集将允许该团队在光学波段从几分钟到十年的时间尺度上研究AGN的变化，在频率上跨越五个数量级。这个项目的AGN样本接近1万个，比以前的研究要大得多。结合x射线波段的其他调查，该团队将测量AGN在光学和x射线波段之间的相关变异性特征。该团队还将培训一名研究生和几名本科生。此外，该团队还将进一步丰富俄克拉荷马州中部K-12学校的便携式天文馆项目。这些活动每年将影响1200名K-12学生，让拟议教育项目的参与者获得高质量的学习体验，加强他们的STEM内容知识，并激励下一代学生在STEM职业中追求并脱颖而出。ASAS-SN是一个分布在全球各地的小型望远镜网络，每天对亮度超过18等的天体进行全天监测。ASAS-SN积累了10年的监测数据，这使得在光学波段对大量明亮AGN样本进行AGN变异性研究成为可能。这些明亮的AGN也将由TESS在10-30分钟的短时间尺度上从太空监测。结合ASAS-SN和TESS数据将允许AGN在频率空间中的五个数量级的光学变异性研究，探测分钟到十年的时间尺度。ASAS-SN、TESS、Swift和RXTE巡天的结合为共同研究明亮AGN的光学和x射线变异性提供了独特的数据集。该项目由MPS/天文科学部（AST）和刺激竞争性研究的既定计划（EPSCoR）共同资助。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。

This project will comprehensively investigate the variation of radiation emitted from supermassive black holes that are actively accreting matter. Almost all galaxies harbor a supermassive black hole at their centers, and their active galactic nuclei (AGN) emit an enormous amount of energy, which can surpass that of all the stars in the galaxy. AGN radiation is varying over time, and this variability is random or stochastic, which encodes important AGN accretion physics. The team will analyze the dataset from two surveys: the All-Sky Automated Survey for Supernovae (ASAS-SN) and the Transiting Exoplanet Survey Satellite (TESS). The combined datasets will allow the team to study AGN variability in the optical band from minutes to decade time scales, spanning five orders of magnitude in frequency. The AGN sample of this project is approaching 10,000, significantly larger than previous studies. Combining with other surveys in the X-ray band, the team will measure the correlated variability characteristics of AGN between optical and X-ray bands. The team will also train a graduate student and several undergraduate students. In addition, the team will further enrich a portable planetarium program for K-12 schools in central Oklahoma. These activities will impact 1,200 K-12 students annually, engage participants of the proposed educational programs in quality learning experiences that strengthen their STEM content knowledge, and inspire the next generation of students to pursue and excel in STEM careers. ASAS-SN is a network of small telescopes distributed around the globe to provide daily, all-sky monitoring of celestial objects brighter than 18th magnitude. ASAS-SN has accumulated 10 years of monitoring data, and this enables AGN variability studies in the optical band for a large sample of bright AGN. These bright AGN will also be monitored from space by TESS in short time-scales with 10–30 minute cadences. The combined ASAS-SN and TESS data will allow AGN optical variability study in five orders of magnitude in the frequency space, probing minute to decade timescales. The combination of ASAS-SN, TESS, Swift, and RXTE surveys provide a unique data set to jointly study optical and X-ray variability of bright AGN. This project is jointly funded by MPS/Division of Astronomical Sciences (AST) and the Established Program to Stimulate Competitive Research (EPSCoR).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.