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

TL;DR

This study observed a high-temperature flux rope at 7 MK during a filament eruption on the Sun, using advanced image processing to isolate its thermal structure, providing insights for modeling coronal mass ejections.

Contribution

It introduces a method to isolate high-temperature flux rope structures in AIA data, enhancing understanding of their thermodynamic properties during eruptions.

Findings

Flux rope observed at 7 MK in high-temperature channels.

The flux rope's temperature matches DEM analysis results.

Method effectively isolates high-temperature plasma structures.

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.