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，这意味着那些仅比太阳高几倍，是通过掉入黑洞中的光线来检测到的，这一过程是天文学家称为积聚的过程。 该插入物质被加热到高温，从而使其辐射。 黑洞积聚是一个非常复杂的过程：不同的黑洞可以具有非常不同的亮度或光度，并且单个黑洞的光度通常会随时间而变化。 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积聚。 他们将使用尖端的模拟研究三种不同的增积度范围，并与合作者合作，将其结果与相应的光度状态的观察直接进行比较。目的是解决一些长期存在的难题，并将物理解释附加到观察现象上。 期望至少有六名本科生将参与该项目，从而获得了极大的机会，可以暴露于计算天体物理学领域的前列研究。此外，首席研究人员将继续在许多不同的论坛中传播他的研究结果，包括与当地艺术社区的交往，当地学校的演讲，YouTube视频，教育iPad应用程序以及TAP演示的天文学。近年来，在通过数字模拟中了解黑洞的情况下，已经取得了预期的进步。在过去的十年中，将辐射冷却和辐射传输添加到此类模拟中已成为可能开始与观测值进行更紧密的连接和比较。 研究团队将进行三组主要的模拟集，每个模拟针对特定的光度范围。从中等的亮度开始，它们将利用最近将多组辐射传输到其一般相对论辐射磁性水力学代码直接模拟X射线二进制文件的中间光谱状态，包括软光子和硬光子的贡献。 在稍高的亮度（Eddington限制的10-20％）下，他们计划解决长期存在的难题，说明为什么在本质上看起来如此稳定。 从假设强的磁场可以稳定此类磁盘的假设，他们计划测试多个磁场构型，并希望有些人可能导致高磁化强度和稳定性。 最后，他们将将模拟扩展到Eddington限制之外，以考虑超光线X射线源（ULX）。变革性的方面是，模拟将倾斜或倾斜黑洞对称平面中的积聚磁盘。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的评估评估标准的评估值得支持的。

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