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WoU-MMA Collaborative research: Turbulence and Reconnection in Magnetically-Dominated Astrophysical Plasmas

WoU-MMA 合作研究：磁控天体物理等离子体中的湍流和重联

基本信息

批准号：
1903412
负责人：
Lorenzo Sironi
金额：
$ 32.05万
依托单位：
Columbia University
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：
2019-08-01 至 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1903412&HistoricalAwards=false
关键词：
WoU MMA Collaborative research Turbulence

项目摘要

In many astrophysical objects -- like bubbles of magnetic fields and high-energy particles powered by rapidly spinning neutron stars called pulsar wind nebulae -- magnetic fields control the overall dynamics of the hot gas of charged particles, the relativistic astrophysical plasma surrounding the object. In such astrophysical objects dissipation of magnetic energy via magnetic reconnection -- a process where magnetic field lines annihilate, releasing their energy to the particles -- may power the observed high-energy electromagnetic and particle emission. A number of recent observations such as the Crab Nebula gamma-ray flares detected by Fermi and AGILE satellites have emphasized the critical role of magnetic reconnection for the acceleration of the emitting particles in astrophysical high-energy sources. This work will include projects for undergraduate students, and the results will be disseminated to high-school students through dedicated workshops. A new program, "Astro-soup," will be implemented, where serving food to homeless people in New York City will be accompanied by discussion on astrophysical topics of relevance for this work. The overall goal of this research is to explain the puzzling phenomenology of non-thermal emission in the Crab Nebula, the prototype of pulsar wind nebulae and the most famous source in high-energy astrophysics. Its flaring and quiescent signatures will be modeled, from radio to high-energy gamma-rays, in a single physically-grounded scenario based on relativistic magnetic reconnection. Every stage of the research will combine analytical approaches with large-scale first-principles particle-in-cell simulations. The reconnection model of astrophysical high-energy sources will be placed on solid footing by studying from first principles how reconnection layers are self-consistently generated by large-scale flows occurring in the Crab Nebula and how the interplay of reconnection and fluid motions can naturally lead to efficient particle acceleration. The results will also be relevant for other flaring sources, like jets from supermassive black holes, where gamma-ray flares have recently been detected together with neutrino counterparts, thus addressing the goals of NSF's "Windows on the Universe: The Era of Multi-Messenger Astrophysics" 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.

在许多天体中--比如磁场气泡和由快速旋转的中子星提供动力的高能粒子，称为脉冲星风星云--磁场控制着带电粒子热气体的整体动力学，即围绕天体的相对论天体物理等离子体。在这样的天体中，通过磁场重联（磁力线湮灭，将能量释放给粒子的过程）耗散磁能可能会为观测到的高能电磁和粒子发射提供动力。最近的一些观测，如费米和AGILE卫星探测到的蟹状星云伽马射线耀斑，强调了磁重联对天体物理学高能量源中发射粒子加速的关键作用。这项工作将包括针对本科生的项目，其结果将通过专门的讲习班向高中生传播。将实施一个名为“天体汤”的新方案，在向纽约市无家可归者提供食物的同时，还将讨论与这项工作有关的天体物理学主题。这项研究的总体目标是解释蟹状星云中令人困惑的非热发射现象，蟹状星云是脉冲星风星云的原型，也是高能天体物理学中最著名的来源。它的闪耀和静止的签名将被建模，从无线电到高能伽马射线，在一个单一的物理接地的情况下，基于相对论磁重联。研究的每一个阶段都将把联合收割机分析方法与大规模的第一性原理粒子模拟相结合。天体物理学高能量源的重联模型将通过从第一原理研究重联层是如何由蟹状星云中发生的大规模流动自洽地产生的，以及重联和流体运动的相互作用如何自然地导致有效的粒子加速，从而奠定坚实的基础。这些结果也将与其他耀斑源相关，例如来自超大质量黑洞的喷流，其中伽马射线耀斑最近与中微子对应物一起被检测到，从而解决了NSF的“宇宙之窗：多信使天体物理学时代”这个奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。