Multi-Wavelength Observations of Quasi-Periodic Pulsations in a Solar Flare

We report our analysis of multi-wavelength observations of quasi-periodic pulsations (QPPs) during the impulsive phase of the C6.7 flare on 9 May 2019. The flare was simultaneously observed by Fermi , the New Vacuum Solar Telescope , the Mingantu Spectral Radioheliograph , the Nobeyama Radio Polarimeters , and the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory . Three well-pronounced pulsations are detected in full-disk hard X-ray and microwave fluxes, as well as the local light curves at wavelengths of the H α line core, AIA 304 Å, 171 Å, 211 Å, and 335 Å between ≈05:43:30 UT and ≈05:48:15 UT. The quasi-periods of about 90 – 110 seconds are determined from their Morlet wavelet power spectra. Meanwhile, a sequence of three groups of Type-III radio bursts is seen in the radio dynamic spectrum during the same time interval. Our observations suggest that the flare QPPs are possibly related to nonthermal electrons accelerated by the intermittent magnetic reconnection during the flare’s impulsive phase.