Progress in solar flare modeling

报告题目      Progress in solar flare modeling

报告人          Professor Rony KEPPENS 

报告人单位  Centre for mathematical Plasma Astrophysics (CmPA), KU Leuven

报告语言      英

报告时间      20238月24(周四) 上午10:00-12:00

报告地点      1号楼502会议室



The most violent solar plasma process to study is the solar flare, which represents the most energetic explosion in our heliosphere. It involves a dramatic change - or reconnection - in the magnetic topology of the atmosphere, and the so-called "standard solar flare model" collects all observationally established info on flares in a cartoon. This cartoon emphasizes that macroscopic (magnetohydrodynamic) and microscopic (energetic particles) plasma physical processes dynamically interact, although most - if not all - model efforts only simulate the large magnetohydrodynamic (MHD) or the small (kinetic) scales. I will present our first self-consistent model of a standard solar flare [1], where electron beam physics dynamically couples to a large-scale, multi-dimensional magnetohydrodynamic evolution of a flaring arcade. By varying the magnetic field strength, we  explore the various flare classes, and we can compare with 1D flare models to point out the multi-dimensional aspects they lack. In [2], we continued simulating the hour-long postflare behaviour, to ensure that the hot meets the cold: the first numerical demonstration of postflare coronal rain due to thermal instability! I will show some recent results on 3D standard flare modeling, where we obtained [3] Kelvin-Helmholtz induced turbulent looptops consistent with observed non-thermal broadenings, and where we find clear multi-phase behaviour in the gradual phase. All simulation efforts use our open-source MPI-AMRVAC simulation toolkit [4], where grid-adaptivity is essential to zoom in on details that can be resolved by future observing facilities.

[1] W. Ruan et al., 2020, ApJ 896, 97 (18pp) doi:10.3847/1538-4357/ab93db 

[2] W. Ruan et al., 2021, ApJ Letter 920, L15 (8pp) doi:10.3847/2041-8213/ac27b0

[3] W. Ruan et al. 2023, ApJ 947, 67 (10pp) doi:10.3847/1538-4357/ac9b4e

[4]  [4]  Keppens et al., 2012, JCP 231, 718; Porth et al., 2014, ApJS 214, 4; Xia et al., 2018, ApJS 234, 30; Keppens et al, 2021, CAMWA 81, 316, Keppens et al., 2023, A&A 673, A66 doi:10.1051/0004-6361/202245359 




Dr. Rony Keppens is a senior  professor in the Centre for mathematical Plasma Astrophysics (CmPA), KU Leuven. He graduated with top honors in Mathematics, achieving distinguished recognition for both his MSc and PhD degrees from KU Leuven, Belgium. He is an expert in Astroplasma Physics, especially in the fields of computational and theoretical magnetohydrodynamics. He authored influential texts on MHD and led important projects, such as the open-source MPI-AMRVAC code for solar and astrophysical simulations. This code is widely used and highly recognized in the scientific community, which has substantially enriched our understanding of many complex  physical processes. His research interests cover many astrophysical phenomenon, such as stellar winds, astrophysical jets, solar flares and prominences. His papers known to ADS have been cited 6100+ times, and his  current h-index is 43 so far.