Excitation of Multi-periodic Kink Motions in Solar Flare Loops: Possible Application to Quasi-periodic Pulsations
| Autor: | Mijie Shi, Bo Li, Shao-Xia Chen, Mingzhe Guo, Shengju Yuan |
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| Rok vydání: | 2023 |
| Předmět: |
Science & Technology
INSTABILITY WAVES FOS: Physical sciences Astronomy and Astrophysics PROPAGATION Astronomy & Astrophysics MICROWAVE EMISSION LEAKY Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Physical Sciences RECONNECTION OSCILLATIONS Solar and Stellar Astrophysics (astro-ph.SR) |
| DOI: | 10.48550/arxiv.2301.05382 |
| Popis: | Magnetohydrodynamic (MHD) waves are often invoked to interpret quasi-periodic 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 = 57s being attributed to the radial fundamental kink mode and the short-period component P_S=5.8s 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 with such customary interpretations as sausage modes. Comment: Accepted for publication in ApJL |
| Databáze: | OpenAIRE |
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