Cold Solar Flares. I. Microwave Domain

0583577 - ASÚ 2024 RIV GB eng J - Journal Article
Lysenko, A. L. - White, S. M. - Zhdanov, S.A. - Motorina, Galina … Total 7 authors
Cold Solar Flares. I. Microwave Domain.
Astrophysical Journal. Roč. 954, č. 2 (2023), č. článku 122. ISSN 0004-637X. E-ISSN 1538-4357
R&D Projects: GA MŠMT LM2023059; GA ČR(CZ) GC21-16508J; GA MŠMT(CZ) LM2018106
Institutional support: RVO:67985815
Keywords : active solar corona * solar flares * solar radio emission
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 4.9, year: 2022
Method of publishing: Open access

We focus on the microwave emission. The thermal response is evaluated by the soft X-ray emission measured by the GOES X-ray sensors. We obtain spectral parameters of the flare gyrosynchrotron emission and reveal patterns of their temporal evolution. The main results of the previous statistical study are confirmed: as compared to a “mean” flare, the cold flares have shorter durations, higher spectral peak frequencies, and harder spectral indices above the spectral peak. Nonetheless, there are some cold flares with moderate and low peak frequencies. In the majority of cold flares, we find evidence of the Razin effect in the microwave spectra, indicative of rather dense flaring loops. We discuss the results in the context of the electron acceleration efficiency.
Permanent Link: https://hdl.handle.net/11104/0351585