Energetics of a solar flare and a coronal mass ejection generated by a hot channel eruption

Abstract

Hot channels (HCs) are prevalent in the solar corona and play a critical role in driving flares and CMEs. In this paper, we estimate the energy contents of an X1.4 eruptive flare with a fast CME generated by a HC eruption on 2011 September 22. Originating from NOAA AR11302, the HC is the most dramatic feature in 131 and 94 {\AA} images observed by SDO/AIA. The flare is simultaneously observed by SDO/AIA, RHESSI, and STEREO-B/EUVI. The CME is simultaneously detected by the white-light coronagraphs of SOHO/LASCO and STEREO-B/COR1. Using multiwavelength and multiview observations of the eruption, various energy components of the HC, flare, and CME are calculated. The thermal and kinetic energies of the HC are (1.77$\pm$0.61)$\times10^{30}$ erg and (2.90$\pm$0.79)$\times10^{30}$ erg, respectively. The peak thermal energy of the flare and total radiative loss of SXR-emitting plasma are (1.63$\pm$0.04)$\times10^{31}$ erg and (1.03$-$1.31)$\times10^{31}$ erg, respectively. The ratio between the thermal energies of HC and flare is 0.11$\pm$0.03, suggesting that thermal energy of the HC is not negligible. The kinetic and potential energies of the CME are (3.43$\pm$0.94)$\times10^{31}$ erg and (2.66$\pm$0.49)$\times10^{30}$ erg, yielding a total energy of (3.69$\pm$0.98)$\times10^{31}$ erg for the CME. Continuous heating of the HC is required to balance the rapid cooling by heat conduction, which probably originate from intermittent magnetic reconnection at the flare current sheet. Our investigation may provide insight into the buildup, release, and conversion of energies in large-scale solar eruptions.