Revealing Evolution of Electrons and Magnetic Field in Solar Flares

现代太阳物理学通过新的观测来探索太阳，与几年前相比，由于最近技术的进步，光谱覆盖范围和空间、光谱和时间分辨率都有了惊人的提高。与此同时，数据的复杂性和数量也在成比例地增加。这个为期三年的项目的主要目标是将这些多维观测与理论、分析工具和建模紧密结合起来，以获得新的知识，并在太阳物理学方面取得基础科学发现，特别是关于太阳活动物理驱动因素的本质。太阳活动主要依赖于日冕磁场，从广义上讲，日冕磁场包括磁场的产生、形态/拓扑的控制、时间演化、日冕中动能、热能和非热能的转化，以及磁结构和热结构之间的耦合。测量日冕磁场及其在动态时间尺度上的变化的能力对于揭示驱动太阳耀斑、喷发和活动的基本物理是至关重要的。虽然缺乏可靠的日冕磁场直接测量，但该项目旨在通过充分利用最终可用的大量高分辨率数据和建模，从根本上改变这种情况。具体来说，一个实际的机会，常规使用无线电观测太阳日冕，探测涉及太阳耀斑的磁结构，最近首次成为可用的新的，全功能的微波干涉仪- NJIT的扩展欧文斯谷太阳能阵列(EOVSA) -已经开始定期干涉太阳观测。为了理解这些高要求的数据，随着体积和复杂性的逐渐增加，并将这些数据整合到太阳耀斑中磁和热结构以及加速非热电子的完整合成图像中，该项目将利用复杂的模型，将最先进的理论，计算代码和模拟工具与数据相结合。该项目包括广泛传播在太阳射电天文学中收集到的新知识，以提高对太阳物理学和整个天体物理学的科学认识。EOVSA观测的基本性质确保了对太阳物理领域的广泛影响，包括DIKIST， FASR等未来仪器的开发。这项工作将产生用户友好的软件工具，这些软件工具将通过Solarsoft IDL分发库广泛提供给太阳和空间天气社区。这些建模工具将在NJIT的日地研究中心（CSTR）的暑期实习中使用，在那里，项目团队招募当地的初中学生参与尖端的太阳能研究。此外，在NJIT的CSTR提供的高度多样化的环境中进行，各种项目活动将促进发现和理解，同时促进教学，培训和学习。特别是，在这个项目中开发的易于使用的工具将成为很好的学习工具，这些工具将广泛用于CSTR的研究生课程，如“射电天文学”、“太阳物理学”和“等离子体物理学和MHD”。这个为期三年的项目强调了EOVSA通过动态测量日冕磁场以及高时空分辨率的热电子和非热电子分布来量化太阳耀斑演变的独特能力。该项目的目标包括：(i)获得日冕磁场和耀斑环内电子分布的演化图；（ii）建立持续演变的太阳耀斑三维模型，通过正拟合，同时拟合所有可用数据，包括磁场、无线电、x射线、极紫外线等；（三）向科学家和公众开放获取这些产品。项目团队将采用一种综合研究方法，将来自EOVSA的新微波成像数据、来自其他地面仪器的数据以及来自最新太空任务的数据结合先进的建模和前向拟合，获得耀斑环中的三维磁场和粒子分布。该项目的研究和EPO议程支持AGS部门在发现、学习、多样性和跨学科研究方面的战略目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Modern solar physics explores the Sun through new observations with fantastically improved spectral coverage and spatial, spectral, and temporal resolutions relative to only a few years ago, brought about by recent advances in technology. In parallel, the complexity and volume of the data have been increasing proportionally. The main goal of this three-year project is to tightly couple these multi-dimensional observations with theory, analysis tools, and modeling to obtain new knowledge and make fundamental scientific discoveries in solar physics, particularly about the nature of the physical drivers of the solar activity. The solar activity depends critically on coronal magnetism, which, broadly speaking, includes magnetic field generation, control of morphology/topology, temporal evolution, and transformation into kinetic, thermal, and non-thermal energies in the Sun's corona, as well as coupling between the magnetic and thermal structures. The ability to measure the coronal magnetic field and its changes on dynamic time scales is critically needed to uncover fundamental physics driving solar flares, eruptions, and activity. While reliable direct measurement of coronal magnetic fields has been lacking, this project aims to radically change the situation by taking full advantage of the large wealth of high resolution data and modeling that is finally becoming available. Specifically, a practical opportunity for routine use of radio observations of the Sun's corona for probing the magnetic structures involved in solar flares has recently become available for the first time from the new, fully functional microwave interferometer -- the NJIT's Expanded Owens Valley Solar Array (EOVSA) -- which has started regular interferometric observations of the Sun. To make sense of these highly demanding data, with progressively increasing volume and complexity, and to integrate these data into a full synthetic picture of the magnetic and thermal structure along with accelerated non-thermal electrons in solar flares, this project will utilize sophisticated models that combine the most advanced theories, computational codes, and simulation tools with the data.This project includes broad dissemination of the new knowledge gathered in solar radio-astronomy to enhance scientific understanding not only in solar physics, but also throughout astrophysics. The fundamental nature of EOVSA's observations ensures a broad impact on the field of solar physics, including future instrument development for the DIKIST, FASR, etc. The work will result in user-friendly software tools that will be made widely available to the solar and space weather community through the Solarsoft IDL distribution library. These modeling tools will be used during the summer internships at the NJIT's Center for Solar-Terrestrial Research (CSTR), where the project team recruits local junior high school students to participate in cutting-edge solar research. In addition, being performed within highly diverse environment provided by the CSTR at NJIT, the various project activities will advance discovery and understanding, while promoting teaching, training and learning. In particular, the easy-to-use tools to be developed during this project make great learning tools that will be widely used in graduate courses at the CSTR, such as "Radio Astronomy," "Solar Physics," and "Plasma Physics and MHD."The three-year project emphasizes the unique ability of EOVSA to quantify evolution of solar flares by dynamically measuring coronal magnetic fields along with the thermal and non-thermal electron distributions with high spatial and temporal resolution. The project objectives include: (i) obtain evolving maps of coronal magnetic field and electron distributions in the flaring loops; (ii) build consistent evolving three-dimensional models of solar flares that, through forward fitting, simultaneously fit all available data, including the magnetic field, radio, X-ray, EUV and others; and, (iii) provide open access to these product to the scientists and the public. The project team will adopt an integrated research approach that brings together new microwave imaging data available from the EOVSA, data from other ground-based instruments as opportunities allow, and data from the latest space missions, coupled with advanced modeling and forward-fitting, to obtain the three-dimensional magnetic field and particle distributions in flaring loops. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.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.