RUI: Understanding Black Hole Accretion Across a Range of Luminosities

RUI：了解不同光度范围内的黑洞吸积

• 批准号: 1907850
• 负责人: Patrick Fragile
• 金额: $ 28.4万
• 依托单位: College of Charleston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907850&HistoricalAwards=false
• 关键词: RUI; Understanding; Black; Hole; Accretion

Stellar-mass black holes, meaning those only a few times more massive than the Sun, are detected via the light given off by matter falling into the black hole, a process that astronomers call accretion. This infalling matter is heated to high temperatures, causing it to radiate. Black hole accretion is a very complicated process: different black holes can have very different brightness, or luminosity, and the luminosity of an individual black hole usually varies considerably with time. A research group at the College of Charleston will study black hole accretion using numerical computer simulations. They will study three different accretion regimes, in distinctly different luminosity ranges, using cutting-edge simulations, and working with collaborators to compare their results directly with observations of the corresponding luminosity states. The goal is to solve some long-standing puzzles and attach physical explanations to observational phenomena. The expectation is that at least six undergraduate students will be involved in the project, gaining an exceptional opportunity to be exposed to forefront research in computational astrophysics. Additionally, the principal investigator will continue to disseminate his research results in a number of diverse forums, including engagements with the local arts community, presentations in local schools, YouTube videos, educational iPad apps, and Astronomy on Tap presentations.Tremendous progress has been made in recent years in understanding black hole accretion through numerical simulations. The addition of radiative cooling and radiation transport to such simulations over the past decade has made it possible to begin to make tighter connections and comparisons with observations. The research team will conduct three main sets of simulations, each targeting a specific luminosity range. Beginning at moderate luminosities, they will leverage the recent addition of multi-group radiation transport to their general relativistic radiation magnetohydrodynamics code to directly model the intermediate spectral states of X-ray binaries, including both the soft and hard photon contributions. At slightly higher luminosities, 10-20% of the Eddington limit, they plan to tackle the long-standing puzzle as to why disks in this range appear so stable in nature. Working from the hypothesis that strong magnetic fields may stabilize such disks, they plan to test multiple magnetic field configurations with the expectation that some may lead to high magnetization and stability. Lastly, they will extend their simulations beyond the Eddington limit to consider ultra-luminous X-ray sources (ULXs). The transformative aspect will be that the simulations will tilt, or incline, the accretion disk out of the black hole symmetry plane.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.

恒星质量的黑洞，意味着那些质量仅比太阳大几倍的黑洞，通过落入黑洞的物质发出的光被探测到，这一过程被天文学家称为吸积。 这种下落的物质被加热到高温，导致它辐射。 黑洞吸积是一个非常复杂的过程：不同的黑洞可以有非常不同的亮度，或者光度，并且单个黑洞的光度通常随时间而变化。 查尔斯顿学院的一个研究小组将使用数值计算机模拟研究黑洞吸积。 他们将研究三种不同的吸积机制，在明显不同的光度范围内，使用尖端的模拟，并与合作者直接比较他们的结果与相应的光度状态的观察。目标是解决一些长期存在的难题，并为观测现象提供物理解释。 预计至少有六名本科生将参与该项目，获得接触计算天体物理学前沿研究的绝佳机会。此外，首席研究员将继续在各种论坛上传播他的研究成果，包括与当地艺术界的接触，在当地学校的演讲，YouTube视频，教育iPad应用程序和Astronomy on Tap演示。近年来，通过数值模拟了解黑洞吸积已经取得了巨大进展。在过去十年中，在这种模拟中增加了辐射冷却和辐射输送，使得开始与观测进行更紧密的联系和比较成为可能。 研究小组将进行三组主要的模拟，每组模拟都针对特定的光度范围。从中等亮度开始，他们将利用最近增加的多群辐射输运到他们的广义相对论辐射磁流体动力学代码中，直接模拟X射线双星的中间光谱状态，包括软光子和硬光子的贡献。 在略高的光度下，即爱丁顿极限的10-20%，他们计划解决长期存在的难题，即为什么在这个范围内的圆盘在自然界中如此稳定。 从强磁场可能稳定这些磁盘的假设出发，他们计划测试多种磁场配置，期望其中一些可能导致高磁化和稳定性。 最后，他们将把模拟扩展到爱丁顿极限之外，以考虑超亮X射线源（ULX）。变革性的方面将是模拟将倾斜，或倾斜，吸积盘的黑洞对称plane.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Simulations of Precessing Jets and the Formation of X-shaped Radio Galaxies

进动喷流和 X 形射电星系形成的模拟

• DOI: 10.3847/1538-4357/acc652
• 发表时间: 2023
• 期刊: The Astrophysical Journal
• 作者: Nolting, Chris;Ball, Jay;Nguyen, Tri M.
• 通讯作者: Nguyen, Tri M.

The luminous, hard state can’t be MAD

发光的硬态不可能是疯狂的

• DOI: 10.1093/mnrasl/slad099
• 发表时间: 2023
• 期刊: Monthly Notices of the Royal Astronomical Society: Letters
• 作者: Fragile, P. Chris;Chatterjee, Koushik;Ingram, Adam;Middleton, Matthew
• 通讯作者: Middleton, Matthew

Neutron star QPOs from oscillating, precessing hot, thick flow

来自振荡、进动的热稠流的中子星 QPO

• DOI: 10.1093/mnras/stz3269
• 发表时间: 2019
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Fragile, P. Chris

Looking for the underlying cause of black hole X-ray variability in GRMHD simulations

• DOI: 10.1093/mnras/staa1808
• 发表时间: 2020-06
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: D. Bollimpalli;D. Bollimpalli;Ra’ad D Mahmoud;C. Done;P. C. Fragile;P. C. Fragile;W. Klu'zniak

Interactions of type I X-ray bursts with thin accretion disks

• DOI: 10.1038/s41550-019-0987-5
• 发表时间: 2020-01
• 期刊: Nature Astronomy
• 影响因子: 14.1
• 作者: P. C. Fragile;D. Ballantyne;Aidan Blankenship