Recurrent Narrow Quasiperiodic Fast-propagating Wave Trains Excited by the Intermittent Energy Release in the Accompanying Solar Flare

Abstract

About the driven mechanisms of the quasiperiodic fast-propagating (QFP) wave trains, there exist two dominant competing physical explanations: they are associated with the flaring energy release or attributed to the waveguide dispersion. Employing Solar Dynamics Observatory/Atmospheric Imaging Assembly 171 Å images, we investigated a series of QFP wave trains composed of multiple wave fronts propagating along a loop system during the accompanying flare on 2011 November 11. The wave trains showed a high correlation in start times 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 considered 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 G. Meanwhile, we also estimated that the energy flux of the wave trains was about 1.2 × 105 erg cm−2 s−1.