Radiation GRMHD with Non-Thermal Particle Acceleration: Next-Generation Models of Black Hole Accretion Flows and Jets

射电望远镜揭示的最惊人的现象之一是相对论喷流，它可以延伸超过一百万秒，并已被证明与巨型椭圆星系中心的超大质量黑洞(SMBH)有物理联系。尽管经过了几十年的努力，我们对气体吸积到旋转的SMBH上的步骤的理解仍然不完整。广义相对论磁流体力学(GRMHD)流体模拟最近显示出能够正确解释相关物理的前景，并成功地再现了低光度活动星系核(AGN)中的喷流功率和结构，以及预测了事件视界望远镜M87和SgrA*的图像。首席研究人员将领导一个团队，开发适用于更广泛的活动星系核光度的下一代GRMHD代码，将喷流的多波长观测与中央SMBH及其附近环境的性质联系起来。该奖项还将支持博士后在最先进的计算技术方面的培训，为本科生提供研究机会，并发展公共天文表演。所有GRMHD模型和源代码都将公之于众。下一代GRMHD模型将用于预测从大范围的低亮度吸积流和喷流产生的射电到伽马射线的发射。这些将被用来解决关于热吸积流结构的长期问题，包括相对论电子如何被加载到喷流中导致它们辐射能量的根本问题。电子分布函数将使用粒子加速的动力学处方和辐射冷却的频率依赖的蒙特卡罗方法来演变。GRMHD模拟将持续足够长的时间来建立从黑洞到~100引力半径的平衡性质，以便可靠地预测吸积流和喷流结构。从模拟计算的宽带谱和极化无线电发射图作为(例如)的函数质量吸积率将与代表性来源的观测结果进行比较，并用于预测下一代长基线无线电干涉仪的黑洞阴影能见度。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

One of the most striking phenomena revealed by radio telescopes are relativistic jets that can stretch over a million parsecs and have been shown to be physically connected with supermassive black holes (SMBH) in the centers of giant elliptical galaxies. Despite decades of effort, our understanding of the steps by which gas accreting onto a spinning SMBH is collimated into a narrow, magnetized beam of electrons and launched at near light-speed is still incomplete. General Relativistic Magneto-Hydrodynamic (GRMHD) fluid simulations have lately shown promise in being able to correctly account for the relevant physics and have successfully reproduced jet power and structure in low-luminosity active galactic nuclei (AGN), as well as predicting the Event Horizon Telescope's images of M87 and Sgr A*. The principal investigator will lead a team that will develop next-generation GRMHD code appropriate for a wider range of AGN luminosities that will link multi-wavelength observations of jets to properties of the central SMBH and its near environment. The award will also support the training of a postdoc in state-of-the-art computational techniques, provide opportunities for undergraduate research, and develop public planetarium shows. All GRMHD models and source code will be made publicly available.The next-generation GRMHD models will be used to predict radio to gamma-ray emission from a broad range of low-luminosity accretion flows and jets. These will be used to address longstanding questions about the structure of hot accretion flows, including the fundamental question of how relativistic electrons are loaded into jets causing them to radiate energy. The electron distribution function will be evolved using kinetic prescriptions for particle acceleration and a frequency- dependent, Monte Carlo method for radiative cooling. GRMHD simulations will be run for a sufficiently long duration to establish equilibrium properties up to ~100 gravitational radii from the black hole, in order to reliably predict the accretion flow and jet structure. Broadband spectra and polarized radio emission maps computed from the simulations as a function of (e.g.) mass accretion rate will be compared to observations of representative sources and used to make predictions for the visibility of the black hole shadow for next-generation long baseline radio interferometers.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.