Spectra and Variability of Black Hole Accretion Disk Models Built on Magnetorotational Turbulence

基于磁旋转湍流的黑洞吸积盘模型的光谱和变异性

• 批准号: 0707624
• 负责人: Omer Blaes
• 金额: $ 53.69万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0707624&HistoricalAwards=false
• 关键词: Spectra; Variability; Black; Hole; Accretion

AST-0707624BlaesAccretion disk theory has been undergoing a slow but steady revolution ever since the discovery that turbulence driven by the magnetorotational instability (MRI) is likely to be responsible for outward angular momentum transport. Thanks in large part to simulations of MRI turbulence, scientists are for the first time getting a handle on the true vertical structure of accretion disks, free of ad hoc assumptions. This project will analyze new simulations with radiation pressure much larger than gas pressure. This radiation pressure-dominated regime is the most uncertain and at the same time the most important for understanding the innermost regions of luminous accretion disks around black holes. The study will also rebuild spectral models of accretion disks, applicable to both stellar mass black hole X-ray binaries and supermassive black holes in quasars and active galactic nuclei. The techniques include Monte Carlo methods to handle radiative transfer.In further activity, the group will analyze local and global MRI simulations, perform analytic calculations of linear modes and nonlinear driving and damping, and simulate linear instabilities in magnetically dominated configurations. The end result will be a complete understanding of the true vertical structure of accretion disks around black holes in all regimes, from the gas pressure dominated outer regions to the radiation pressure dominated inner regions. The spectral models will be fully predictive for the first time, as they are based on physics and not ad hoc assumptions. This research will lead to a deep understanding of the expected variability of MRI flow structures based on combining analytic and quasi-analytic linear mode theory and local and global simulations.The project will be the main vehicle for the theses of two graduate students, one concentrating on numerical simulations, and the other focused mainly on analytic calculations and numerical spectral modeling. The researchers will also continue to engage the public in exciting developments in black hole astrophysics, using movies and images from numerical simulations as well as music-based ideas to explain black hole X-ray variability.

自从发现由磁致旋转不稳定性(MRI)驱动的湍流很可能是向外角动量输运的原因以来，AST-0707624 BleseConcretion Disk理论经历了一场缓慢而稳定的革命。这在很大程度上要归功于对核磁共振湍流的模拟，科学家们第一次能够掌握吸积盘的真实垂直结构，而不是特别的假设。这个项目将分析辐射压力远大于气体压力的新模拟。这种辐射压力主导的区域是最不确定的，同时也是理解黑洞周围发光吸积盘最内部区域的最重要的区域。这项研究还将重建吸积盘的光谱模型，适用于恒星质量黑洞X射线双星和类星体和活动星系核中的超大质量黑洞。这些技术包括处理辐射传输的蒙特卡罗方法。在进一步的活动中，该小组将分析局部和全局MRI模拟，执行线性模式和非线性驱动和阻尼的解析计算，并模拟磁性主导构型中的线性不稳定性。最终的结果将是在所有区域，从气体压力占主导地位的外部区域到辐射压力占主导地位的内部区域，完全了解黑洞周围吸积盘的真实垂直结构。光谱模型将首次完全具有预测性，因为它们是基于物理而不是特别的假设。这项研究将基于解析和准解析线性模式理论以及局部和全局模拟，深入了解MRI流动结构的预期变异性。该项目将成为两名研究生论文的主要载体，一名专注于数值模拟，另一名主要专注于解析计算和数值光谱模拟。研究人员还将继续让公众参与黑洞天体物理学的令人兴奋的发展，使用来自数值模拟的电影和图像，以及基于音乐的想法来解释黑洞X射线的可变性。