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

Quasi-periodic pulsations (QPPs) 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) on board the Solar Dynamics Observatory and the Nobeyama Radioheliograph (NoRH) to observe an M7.7 class flare that occurred at active region 11520 on 2012 July 19. A QPP was detected both in the AIA 131 $\mathring{\rm A} $ bandpass and the NoRH 17 $\mathrm{GHz}$ 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 $\mathring{\rm A} $ 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.