Numerical Modeling of Energetic Electron Acceleration, Transport, and Emission in Solar Flares: Connecting Loop-top and Footpoint Hard X-Ray Sources
Numerical Modeling of Energetic Electron Acceleration, Transport, and Emission in Solar Flares: Connecting Loop-top and Footpoint Hard X-Ray Sources
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太阳耀斑中高能电子加速、传输和发射的数值模拟：连接环顶和足点硬 X 射线源
DOI：
10.3847/2041-8213/aca65c
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发表时间：
2022-11
期刊：
影响因子：
--
通讯作者：
Joe Giacalone
中科院分区：
文献类型：
--
作者：
Xiangliang Kong;Bin Chen;Fan Guo;Chengcai Shen;Xiaocan Li;Jing Ye;Lulu Zhao;Zelong Jiang;Sijie Yu;Yao Chen;Joe Giacalone
太阳耀斑期间高能电子的加速和输运是太阳物理学的重要课题之一。最近的X射线和无线电成像和光谱观测提供了非热电子分布的诊断，并建议在某些耀斑事件中，电子主要在环顶部加速，并可能经历捕获和/或散射效应。结合磁流体动力学（MHD）模拟太阳耀斑的聚焦粒子输运方程，我们提出了一个宏观粒子模型，自然包括电子加速和运输。我们的模拟结果表明，物理过程，如湍流俯仰角散射可以有重要的影响，电子加速在环顶和耀斑环中的运输，和他们的影响是高度依赖于能量。在环顶部具有增强的空间依赖性湍流散射可以实现有效的电子加速到高能量和将丰富的电子传输到足点。我们进一步生成空间分辨的合成硬X射线（HXR）发射图像和光谱，揭示了环顶和足点HXR源。与观测结果类似，我们发现足点HXR源比环顶HXR源更亮更硬。我们认为，宏观粒子模型提供了新的见解，了解所观察到的环顶和脚点非热发射源之间的连接相结合的粒子模型与动态演变的MHD模拟太阳耀斑。
The acceleration and transport of energetic electrons during solar flares is one of the outstanding topics in solar physics. Recent X-ray and radio imaging and spectroscopy observations have provided diagnostics of the distribution of nonthermal electrons and suggested that, in certain flare events, electrons are primarily accelerated in the loop top and likely experience trapping and/or scattering effects. By combining the focused particle transport equation with magnetohydrodynamic (MHD) simulations of solar flares, we present a macroscopic particle model that naturally incorporates electron acceleration and transport. Our simulation results indicate that physical processes such as turbulent pitch-angle scattering can have important impacts on both electron acceleration in the loop top and transport in the flare loop, and their influences are highly energy-dependent. A spatial-dependent turbulent scattering with enhancement in the loop top can enable both efficient electron acceleration to high energies and transport of abundant electrons to the footpoints. We further generate spatially resolved synthetic hard X-ray (HXR) emission images and spectra, revealing both the loop-top and footpoint HXR sources. Similar to the observations, we show that the footpoint HXR sources are brighter and harder than the loop-top HXR source. We suggest that the macroscopic particle model provides new insights into understanding the connection between the observed loop-top and footpoint nonthermal emission sources by combining the particle model with dynamically evolving MHD simulations of solar flares.
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影响因子：
4.9
作者：
Wang Yulei;Cheng Xin;Ding Mingde;Lu Quanming
通讯作者：
Lu Quanming
影响因子：
6.5
作者：
E. P. Kontar;A. MacKinnon;R. Schwartz;JOHN C. Brown
通讯作者：
E. P. Kontar;A. MacKinnon;R. Schwartz;JOHN C. Brown
DOI：
10.3847/2041-8213/aaedb3
发表时间：
2018-08
期刊：
The Astrophysical Journal Letters
影响因子：
--
作者：
F. Effenberger;V. Petrosian
通讯作者：
F. Effenberger;V. Petrosian
影响因子：
2.8
作者：
P. Saint-Hilaire;S. Krucker;R. Lin
通讯作者：
P. Saint-Hilaire;S. Krucker;R. Lin
DOI：
10.1086/505460
发表时间：
2006-08
期刊：
The Astrophysical Journal
影响因子：
--
作者：
M. Karlický;M. Bárta
通讯作者：
M. Karlický;M. Bárta