Recurrent narrow quasi-periodic fast-propagating wave trains excited by the intermittent energy release in the accompanying solar flare

TL;DR

This study analyzes quasi-periodic fast-propagating wave trains in solar flares, concluding they are triggered by flare energy release rather than waveguide dispersion, with implications for solar seismology and energy flux estimation.

Contribution

It provides evidence that QFP wave trains are flare-triggered and not dispersive, and demonstrates their use in estimating magnetic field strength and energy flux in the solar corona.

Findings

Wave trains are correlated with flare energy release.

Wave phase speed matches group speed (~1000 km/s).

Estimated magnetic field strength is about 10 Gauss.

Abstract

About the driven mechanisms of the quasi-periodic fast-propagating (QFP) wave trains, there exist two dominant competing physical explanations: associated with the flaring energy release or attributed to the waveguide dispersion. Employing Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) 171 A images, we investigated a series of QFP wave trains composed of multiple wavefronts propagating along a loop system during the accompanying flare on 2011 November 11. The wave trains showed a high correlation in start time with the energy release of the accompanying flare. Measurements show that the wave trains phase speed is almost consistent with its group speed with a value of about 1000 km s-1, indicating that the wave trains should not be dispersed waves. The period of the wave trains was the same as that of the oscillatory signal in X ray emissions released by the flare. Thus we propose that the QFP wave trains were most likely triggered by the flare rather than by dispersion. We investigated the seismological application with the QFP waves and then obtained that the magnetic field strength of the waveguide was about 10 Gauss. Meanwhile, we also estimated that the energy flux of the wave trains was about 1.2X105 erg cm-2 s-1.