EUV & X-ray observations of microflare heating of AR12333

Abstract:

We present a study of the heating in AR12333 due to small microflares between 10:30 and 13:30UT on 29 April 2015. This region is well observed in EUV by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) as well as Hinode’s X-ray Telescope (XRT) operating in a higher cadence mode, switching through the five thicker filters (sensitive to the higher temperature range). The Hinode observations were a coordinated campaign with the NuSTAR hard X-ray focusing optics telescope (Harrison et al. 2013). NuSTAR was conducting a full disk mosaic observation of the Sun and caught AR12333 several times, providing imaging spectroscopy >2 keV. We investigate the heating in the active region due to several small microflares (about A1-Class). These were visible with the thicker XRT filters and only clear in EUV once the FeXVIII component was extracted from SDO/AIA 94Å, indicating heating primarily >3MK. Using the regularized inversion method of Hannah & Kontar 2012, we recover the DEM from the SDO/AIA and Hinode/XRT data and compare this to the thermal characteristics derived from NuSTAR.