Informal Astro Talk
AFINO: an automated search for quasi-periodic pulsations in solar flare X-ray data
Solar flares, like many other astrophysical objects, sometimes show evidence of periodic structures in their temporal profiles. Collectively, these signals are often referred to quasi-periodic pulsations (QPP) or quasi-periodic oscillations (QPO). Despite much study the fundamental nature of QPPs solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. The AFINO (Automated Flare Inference of Oscillations) code addresses this longstanding problem by allowing for an automated analysis of a large sample of solar flares from multiple datasets. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1-8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi/Gamma-ray Burst Monitor (GBM) 15-25 keV X-ray data for each of these flares associated with a Fermi/GBM solar flare trigger, a total of 261 events. From this, we determine that ~30% of events observed by GOES and ~8% of events observed by Fermi/GBM show strong evidence of signatures consistent with classical interpretations of QPP, such as periodic MHD wave structures or regimes of periodic magnetic reconnection. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.