Microwave imaging of quasi-periodic pulsations at flare current sheet

Kou, Y., Cheng, X., Wang, Y., Yu, S., Chen, B., Kontar, E. P. and Ding, M. (2022) Microwave imaging of quasi-periodic pulsations at flare current sheet. Nature Communications, 13, 7680. (doi: 10.1038/s41467-022-35377-0) (PMID:36509764) (PMCID:PMC9744830)

Abstract

Quasi-periodic pulsations (QPPs) are frequently detected in solar and stellar flares, but the underlying physical mechanisms are still to be ascertained. Here, we show microwave QPPs during a solar flare originating from quasi-periodic magnetic reconnection at the flare current sheet. They appear as two vertically detached but closely related sources with the brighter ones located at flare loops and the weaker ones along the stretched current sheet. Although the brightness temperatures of the two microwave sources differ greatly, they vary in phase with periods of about 10–20 s and 30–60 s. The gyrosynchrotron-dominated microwave spectra also present a quasi-periodic soft-hard-soft evolution. These results suggest that relevant high-energy electrons are accelerated by quasi-periodic reconnection, likely arising from the modulation of magnetic islands within the current sheet as validated by a 2.5-dimensional magnetohydrodynamic simulation.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kontar, Professor Eduard
• Authors: Kou, Y., Cheng, X., Wang, Y., Yu, S., Chen, B., Kontar, E. P., and Ding, M.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nature Communications
• Publisher: Nature Research
• ISSN: 2041-1723
• ISSN (Online): 2041-1723
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Nature Communications 13: 7680
• Publisher Policy: Reproduced under a Creative Commons License