Excitation of Multiperiodic Kink Motions in Solar Flare Loops: Possible Application to Quasiperiodic Pulsations
| Autor: | Mijie Shi, Bo Li, Shao-Xia Chen, Mingzhe Guo, Shengju Yuan |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal Letters, Vol 943, Iss 2, p L19 (2023) |
| Druh dokumentu: | article |
| ISSN: | 2041-8213 2041-8205 35431547 |
| DOI: | 10.3847/2041-8213/acb3c6 |
| Popis: | Magnetohydrodynamic (MHD) waves are often invoked to interpret quasiperiodic pulsations (QPPs) in solar flares. We study the response of a straight flare loop to a kink-like velocity perturbation using three-dimensional MHD simulations and forward model the microwave emissions using the fast gyrosynchrotron code. Kink motions with two periodicities are simultaneously generated, with the long-period component ( P _L = 57 s) being attributed to the radial fundamental kink mode and the short-period component ( P _S = 5.8 s) to the first leaky kink mode. Forward modeling results show that the two-periodic oscillations are detectable in the microwave intensities for some lines of sight. Increasing the beam size to (1″) ^2 does not wipe out the microwave oscillations. We propose that the first leaky kink mode is a promising candidate mechanism to account for short-period QPPs. Radio telescopes with high spatial resolutions can help distinguish between this new mechanism and such customary interpretations as sausage modes. |
| Databáze: | Directory of Open Access Journals |
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