eROSITA’s Window into the X-ray-Transient Sky: AGN Accretion in the Era of Big Data

eROSITA 洞察 X 射线瞬变天空的窗口：大数据时代的活动星系核吸积

• 批准号: 426551503
• 负责人: Dr. Mirko Krumpe
• 金额: --
• 依托单位: Leibniz-Institut für Astrophysik Potsdam (AIP)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/426551503?language=en
• 关键词: eROSITA; Window; into; ray; Transient

Open questions persist regarding the fueling mechanisms in Active Galactic Nuclei (AGN): What is the average AGN duty cycle? What is the structure and morphology of the innermost accretion flow? How does that flow depend on global accretion rate? Recent optical and X-ray observations have yielded tantalizing clues: rare accretion turn-on/turn off events and variations in line-of-sight columndensities due to transiting discrete clumps. However, progress has been limited by the low number of observed events.We will use the eROSITA X-ray telescope to compile a new, expanded X-ray monitoring variability statistics database for more than 1e6AGN. We will use machine learning to identify new changing-state and changing-obscuration events in AGN as they occur, boosting the currently small number of known events. The accumulated statistics on accretion ignition/quenching events will reveal AGN duty cycles, and our expected multi-wavelength campaigns will monitor how the accretion disk, BLR, and X-ray corona evolve during AGN ignition. We will also monitor about 800 Seyferts for cloud eclipse events, determine clouds' physical properties, and use the accumulated statistics on such events to determine the distribution and physical origin of clouds. We will also measure variability amplitudes in about 60000 AGN as function of mass and redshift. Finally, we will monitor rapid X-ray variability in about 1600 blazars and correlate with contemporaneous Fermi-LAT data to test single- and multi-zone emission models at all normal states, not just during outbursts.eROSITA will yield the only database (for the foreseeable future) combining X-ray monitoring with a statistically significant sample oftarget AGN, and thus the only bulk X-ray identification of new transient events. Our work will yield the first X-ray observation-based estimate for AGN duty cycles, test unification schemes, and constrain how quickly the accretion flow can evolve in AGN ignition events. We will also constrain the distribution of clumpy matter and the rate of observed obscuration transitions, helping us understand X-ray/optical type mismatches. We will also learn if the X-ray variability mechanism in Seyferts evolves with redshift. Our blazar variability subset will help distinguish various current blazar emission models. Our work also sets the stage for additional Big Dataresearch in the mid 2020s that also use machine learning to classify transients.Our collaboration combines complementary expertise spanning timing and spectroscopy of both AGN and Black Hole Binaries and large samples of high-redshift AGN across multiple bandpasses. To cement the collaboration, new PhD students in this project will be bilateral, with joint supervisors from both countries.

关于活动星系核（AGN）的燃料机制，仍然存在一些悬而未决的问题：AGN的平均占空比是多少？最里面的吸积流的结构和形态是什么？这种流动是如何依赖于全球吸积速率的呢？最近的光学和X射线观测已经产生了诱人的线索：罕见的吸积开启/关闭事件和视线柱密度的变化，由于过境离散团块。我们将利用eROSITA X射线望远镜编制一个新的、扩展的1 e6以上活动星系核X射线监测变率统计数据库。我们将使用机器学习来识别活动星系核中发生的新的变化状态和变化遮蔽事件，从而增加目前少量的已知事件。累积的统计吸积点火/淬灭事件将揭示活动星系核的占空比，我们预期的多波长活动将监测吸积盘，BLR和X射线日冕如何在活动星系核点火过程中演变。我们亦会监测约800个赛弗星的云蚀事件，确定云的物理性质，并利用这些事件的累积统计数据来确定云的分布和物理来源。我们还将测量约60000活动星系核中作为质量和红移函数的变率幅度。最后，我们将监测大约1600个blazar的快速X射线变化，并与同期的Fermi-LAT数据相关联，以测试所有正常状态下的单区和多区发射模型，而不仅仅是在爆发期间。eROSITA将产生唯一的数据库（在可预见的未来），将X射线监测与目标AGN的统计学显著样本相结合，因此只有大量的X射线识别新的瞬态事件。我们的工作将产生第一个基于X射线观测的活动星系核占空比的估计，测试统一计划，并限制如何快速的吸积流可以在活动星系核点火事件的演变。我们还将限制clusified物质的分布和观察到的遮蔽转变的速率，帮助我们理解X射线/光学类型的失配。我们还将了解，如果在塞弗茨的X射线可变性机制的红移演变。我们的blazar变异子集将有助于区分各种当前blazar排放模型。我们的工作也为21世纪20年代中期的其他大数据研究奠定了基础，这些研究也使用机器学习来对瞬变进行分类。我们的合作结合了AGN和黑洞双星的时间和光谱学以及多个带通的高红移AGN大样本的互补专业知识。为了巩固合作，该项目的新博士生将是双边的，来自两国的联合导师。