Quasi-periodic Accelerations of Energetic Particles during a Solar Flare

TL;DR

This study reports the detection of non-stationary quasi-periodic pulsations in high-energy particles during a major solar flare, linking these pulsations to repetitive magnetic reconnection and differing acceleration processes for ions and electrons.

Contribution

It provides new observational evidence of quasi-periodic pulsations in energetic particles during a solar flare and explores their association with magnetic reconnection processes.

Findings

Detected quasi-periods of ~50 s and ~90 s in different emissions.

Linked QPPs to repetitive magnetic reconnection.

Identified differences in acceleration or propagation of ions and electrons.

Abstract

We report the observation of non-stationary Quasi-Periodic Pulsations (QPPs) in high-energy particles during the impulsive phase of an X4.8 flare on 2002 July 23 (SOL2002-07-23T00:35). The X4.8 flare was simultaneously measured by the Reuven Ramaty High Energy Solar Spectroscopic Imager, Nobeyama Radio Polarimeters, and Nobeyama Radioheliograph. The quasi-period of about 50 s, determined by the wavelet transform, is detected in the Gamma-ray line emission. Using the same method, a quasi-period of about 90 s is found in Gamma-ray continuum, hard X-ray (HXR) and radio emissions during almost the same time. Our observations suggest that the flare QPPs should be associated with energetic ions and nonthermal electrons that quasi-periodically accelerated by the repetitive magnetic reconnection. The different quasi-periods between Gamma-ray line and continuum/HXR/radio emissions indicate an apparent difference in acceleration or propagation between energetic ions and nonthermal electrons of this solar flare.