Abstract Details
| Name: Bhuwan Joshi Affiliation: Physical Research Laboratory, Udaipur Solar Observatory Conference ID: ASI2017_1283 Title : Pre-flare activities, flux rope eruption and associated X2.7 solar flare from active region NOAA 12339 Authors and Co-Authors : - Abstract Type : Oral Abstract Category : Sun and the Solar System Abstract : We investigate the flux rope eruption and energy release process during an X2.7 flare occurred in the active region NOAA 12339 using E(UV), HXR and metric radio observations. The RHESSI and GOES light curves along with RHESSI images reveal significant pre-flare activities in this active region prior to this large X-class flare. Although the pre-flare X-ray sources were not exactly co-spatial to the main flare but contributed toward the heating of the active region corona. During the X2.7 flare, we observe two prominent HXR bursts up to ~300 keV energies during which spectra showed strong non-thermal characteristics with power-law indices 2.9 and 2.6 respectively. The flare initiated with fast eruption of the flux rope with projected speed as ~1300 km/s. The hot flux rope along with filament material exhibited much faster radial expansion over its lateral expansion. The impetuous eruption of the flux rope occurred in conjunction with the impulsive rise of strong HXR flare emission and metric type III radio burst, implying opening of overlying closed filed lines by magnetic reconnection. The HXR source structures during the evolution of X2.7 flare shows ‘standard’ conjugate footpoint sources without appreciable movement of the looptop sources. The lack of upward movement of the looptop source likely indicates the absence of overlying closed filed lines in the outer envelope of the active region corona due to which magnetic reconnection could not proceeded at larger coronal heights |