A Compact Source for Quasi-Periodic Pulsation in an M-class Solar Flare

TL;DR

This study identifies a compact source of four-minute quasi-periodic pulsations in an M7.7 solar flare, linking the pulsations to intermittent energy injection in the reconnection region, using combined AIA and NoRH observations.

Contribution

It provides the first detailed spatial analysis of a QPP source in a solar flare, revealing its origin and phase relationships through multi-wavelength imaging.

Findings

QPP originated from a compact source overlapping the X-ray source.

The plasma emission intensities were highly correlated within the source region.

The source region displayed phase-distinct oscillating stripes.

Abstract

Quasi-periodic pulsations (QPP) are usually found in the light curves of solar and stellar flares, they carry the features of time characteristics and plasma emission of the flaring core, and could be used to diagnose the coronas of the Sun and remote stars. In this study, we combined the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory and the Nobeyama Radioheliograph (NoRH) to observe an M7.7 class flare occurred at active region 11520 on 19 July 2012. A QPP was detected both in the AIA $131\unit{\AA{}}$ bandpass and the NoRH $17\unit{GHz}$ channel, it had a period of about four minutes. In the spatial distribution of Fourier power, we found that this QPP originated from a compact source and that it overlapped with the X-ray source above the loop top. The plasma emission intensities in the AIA $131\unit{\AA{}}$ bandpass were highly correlated within this region. The source region is further segmented into stripes that oscillated with distinctive phases. Evidence in this event suggests that this QPP was likely to be generated by intermittent energy injection into the reconnection region.