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arXiv · 2601.23046

Stereoscopic Observations of Solar X-ray Sources Explained by a Data-Constrained Magnetohydrodynamic Simulation

Keitarou Matsumoto·Satoshi Inoue·Meiqi Wang·Säm Krucker·Satoshi Masuda·Muriel Zoë Stiefel·Jeongwoo Lee·Bin Chen·Haimin Wang
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Abstract

We investigated the three-dimensional (3D) magnetic structures and dynamics responsible for particle acceleration in an X7.1-class flare that occurred on October 1, 2024, in NOAA active region 13842. We combined stereoscopic hard X-ray (HXR) observations from the Advanced Space-based Solar Observatory/Hard X-ray Imager (HXI) and the Solar Orbiter/Spectrometer Telescope for Imaging X-rays (STIX) with a 3D magnetohydrodynamic (MHD) simulation constrained by observed photospheric magnetic fields. During the two main peaks of the impulsive phase, HXR footpoints appeared at different locations, indicating a migration of the primary reconnection site in the corona. Our data-constrained MHD simulation successfully reproduced the reconnected field lines linking the observed conjugate HXR footpoints. Furthermore, the simulation shows that these primary reconnections occur along a single quasi-separatrix layer (QSL) system. Therefore, the two main peaks of HXR can be interpreted as episodic energy release within the single QSL system. This study demonstrates that the data-constrained MHD model provides a realistic 3D magnetic context for interpreting HXR emission. Notably, STIX observations revealed a vertically distributed thermal HXR source, extending from the footpoints to the looptop, with its centroid migrating between the two peaks. This marks a first step toward understanding the particle acceleration processes in solar flares.

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Keitarou Matsumoto, Satoshi Inoue, Meiqi Wang, Säm Krucker, Satoshi Masuda, Muriel Zoë Stiefel, Jeongwoo Lee, Bin Chen, Haimin Wang. 2026-01-30. Stereoscopic Observations of Solar X-ray Sources Explained by a Data-Constrained Magnetohydrodynamic Simulation. https://doi.org/10.3847/2041-8213%2Fae4000

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