A 7~MK hot Flux Rope Observed by SDO/AIA

Abstract

A filament eruption was observed on October 31, 2010 in the images recorded by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) in its Extreme Ultra-Violet (EUV) channels. The filament showed a slow rise phase followed by a fast rise and was classified to be an asymmetric eruption. In addition, multiple localized brightening which was spatially and temporally associated with the slow rise phase were identified leading us to believe that the tether-cutting mechanism to be the cause of the initiation of the eruption. An associated flux rope was detected in high temperature channels of AIA namely 94\r{A} and 131\r{A} corresponding to 7 MK and 11 MK plasma respectively. In addition, these channels are also sensitive to cooler plasma corresponding to ~1-2 MK. In this study we have applied the algorithm devised by Warren et al. (2012) to remove cooler emission from the 94\r{A} channel to deduce only the high temperature structure of the flux rope and to study its temporal evolution. We found that the flux rope was very clearly seen in clean 94\r{A} channel image corresponding to Fe XVIII emission which corresponds to a plasma at a temperature of 7 MK. This temperature matched well with that obtained using DEM analysis. This study provides important constrains in the modelling of the thermodynamic structure of the flux ropes in CMEs.