Collaborative Research: WoU-MMA: Multi-scale and multi-messenger modeling of jets in active galactic nuclei

星系是数千亿颗恒星的巨大集合。在少数星系中，它们观测到的光主要来自一个单一的光源：位于星系中心的超大质量黑洞。在这些星系中，黑洞以变成非常热的电离气体或等离子体的物质为食。令人惊讶的是，这些物质的一部分从黑洞中喷出，形成以接近光速移动的窄等离子体束。当这些光束射向地球时，它们是宇宙中有史以来观测到的最明亮和极端的光源。 提议的团队计划进行最大规模的数值模拟，研究物质福尔斯如何从星系的巨大尺度落入黑洞的微小尺度，并跟踪狭窄的快速等离子体束在星系中传播时如何形成和发光。数值模拟的结果将通过一个方便用户的互动网站向公众开放。用户（科学家，第二部分冰立方中微子天文台最近探测到一个与耀变体TXS 0506+056多波长耀斑同时发生的极高能中微子事件，这有力地表明耀变体不仅产生高能中微子，高能光子，还有超高能宇宙射线和中微子。这一令人兴奋的多信使发现激发了对相对论喷流物理学的详细研究，以解释这一点和即将到来的活动星系核（AGN）的多信使观测。该团队建议进行多尺度射流模拟，将吸积物理学，流体动力学，粒子加速和辐射传输联系起来，以研究AGN射流的多波长偏振辐射特征和中微子。该团队计划对AGN吸积和喷流进行迄今为止最大的广义相对论磁流体动力学模拟，从黑洞延伸到耀变体发射区。他们将使用第一原理动力学等离子体模拟来计算射流耗散区的粒子加速，并建立包括所有相关物理学的综合多信使偏振辐射传输。通过这种方式，该团队可以弥合第一性原理建模和多信使观测之间的差距，并推进对负责多信使发射的活动星系核喷流物理学的理解。该团队将通过一个沉浸式网站向公众传播结果，培训高中生，并为研究生组织一个紧凑的暑期学校，参与者将在研究领域的前沿研究理论和/或数值问题。该奖项旨在解决/该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的学术价值和更广泛的影响审查标准。

Part 1Galaxies are vast collections of hundreds of billions of stars. In a minority of the galaxies their observed light is dominated by a single source: the supermassive black hole located at their very center. In these galaxies, the black hole feeds on material which turns into very hot ionized gas or plasma. Surprisingly, part of this material is ejected away from the black hole forming narrow beams of plasma that move at near the speed of light. These beams, when directed at Earth, make some of the brightest and extreme sources ever observed in the Universe. The proposing team plans to perform the largest numerical simulations to study how matter falls from the vast scale of the galaxy into the tiny scale of the black hole and follow how the narrow fast beams of plasma form and shine as they propagate through the galaxy. The results from the numerical simulations will be publicly accessible through a user-friendly, interactive website. The user (scientist, teacher or high-school student) will be able to generate images of these beams in real-time and will thus be exposed to an exciting field of modern high-energy astrophysics.Part 2Recent detection by the IceCube Neutrino Observatory of a very high energy neutrino event coincident with multi-wavelength flaring of blazar TXS 0506+056 strongly suggests that blazars do not only produce high-energy photons but also ultra-high-energy cosmic rays and neutrinos. This exciting multi-messenger discovery motivates a detailed study of relativistic jet physics, to interpret this and upcoming multi-messenger observations of active galactic nuclei (AGN). The team proposes to perform multi-scale jet simulations that connect accretion physics, fluid dynamics, particle acceleration, and radiative transfer, to study the multi-wavelength polarized radiation signatures and neutrinos from AGN jets. The team plans to perform the largest to date general relativistic magnetohydrodynamic simulations of AGN accretion and jets, extending from the black hole to the blazar emission zone. They will use first-principle kinetic plasma simulations to calculate particle acceleration in jet dissipation zones and build comprehensive multi-messenger polarized radiative transfer that includes all the relevant physics. In this way, the team can bridge the gap between first-principle modeling and multi-messenger observations, and advance the understanding of AGN jet physics responsible for multi-messenger emission. The team will disseminate the results to the public through an immersive website, train high-school students, and organize a summer school in compact objects for graduate students, where participants will work on theoretical and/or numerical problems at the forefront of the research field.This award addresses/advances the goals of the Windows on the Universe Big Idea.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.