High-resolution Observations of an X6.4 Solar Flare in the Mid-infrared

Autor(es):Mostrar menos -

Yang, Xu ; Cao, Wenda ; Wang, Meiqi ; Jennings, Don ; Qiu, Jiong ; He, Wen ; Perriyil, Solomon M. ; Yurchyshyn, Vasyl ; Fletcher, Lyndsay ; Simoes, Paulo J. A. ; Jhabvala, Murzy ; Lunsford, Allen ; Chen, Xingyao ; Hudson, Hugh

• Tipo de documento: Artigo Científico
• Fonte: Astrophysical Journal Letters; v. 988, n. 2, p. 10-pg., 2025-08-01.

Resumo

We present a unique observation of the X6.4-class flare SOL2024-02-22T22:34 using the Mid-InfraRed Imager (MIRI) at the Goode Solar Telescope. Three ribbon-like flare sources and one unidentified source were detected in MIRI's two mid-infrared (mid-IR) bands at 5.2 and 8.2 mu m. The two stronger ribbons displayed maximum mid-IR enhancements of 21% and 18% above quiet-Sun levels and 10% in Helioseismic and Magnetic Imager (HMI) continuum intensity (I-c). The weak ribbon and the unidentified source had maximum mid-IR enhancements of 7% but showed HMI/I-c dimmings, instead of excess emissions. Our result suggests that mid-IR emission forms in a higher layer during the flare and is more sensitive to flare heating than HMI/I-c emission. The MIRI observations have high temporal resolution (2.6 s cadence in these observations) and show apparent source motions. One flare ribbon extends along weak vertical magnetic-field channels in the sunspot umbra, light bridge, and penumbra, with an approximately 30 s delay between HMI/I-c and 8.2 mu m emissions. Meanwhile, the unidentified source moved at an apparent speed of 130 km s(-1) from a mixed-polarity area to one flare ribbon with a strong HMI/I-c enhancement. We studied available hard X-ray/microwave imaging spectroscopy and used nonlinear force-free field extrapolation modeling to identify flare structures. The observational evidence strongly favors the chromospheric origin of the unidentified mid-IR source. Comparison with the X1.0 flare SOL2022-10-02T20:25 indicates that the total amount of high-energy electron (>60 keV) flux density is a key factor in determining the total brightening area and the maximum intensity enhancement in HMI/I-c emissions. (AU)

• Processo FAPESP: 22/15700-7 - Diagnósticos da cromosfera solar no infra vermelho
• Beneficiário: Carlos Guillermo Giménez de Castro
• Modalidade de apoio: Auxílio à Pesquisa - Regular