Abstracts Details


First Name * : Prabir
Last Name * : Mitra
Affiliation * : Physical Research Laboratory
Abstract Type * : Poster
Title * : Pre-flare Processes, Triggering oQuasi-stable Hot Coronal Channel Leading to Large-scale Solar Eruption and Associated X-class Flare
Author(s) * : Prabir K. Mitra (Physical Research Laboratory), Bhuwan Joshi (Physical Research Laboratory)
Abstract Session * : Solar flares and coronal mass ejections
Abstract * : We present a multi-wavelength analysis of the eruption of a hot coronal channel associated with an X1.0 flare from the active region NOAA 11875 by combining observations from AIA/SDO, HMI/SDO, RHESSI, and HiRAS. EUV images at high coronal temperatures indicated the presence of a hot channel at the core of the active region from the early pre-flare phase evidencing the pre-existence of a quasi-stable magnetic flux rope. The hot channel underwent an activation phase after a localized and prolonged pre-flare event occurring adjacent to one of its footpoints. Subsequently, the flux rope continued to rise slowly for โ‰ˆ16 min during which soft X-ray flux gradually built-up characterizing a distinct precursor phase. The flux rope transitioned from the state of slow rise to the eruptive motion with the onset of the impulsive phase of the X1.0 flare. The eruptive expansion of the hot channel is accompanied by a series of type III radio bursts in association with impulsive rise of strong hard X-ray non-thermal emissions that included explicit hard X-ray sources of energies up to โ‰ˆ50 keV from the coronal loops and โ‰ˆ100 keV from their footpoint locations. Our study contains evidence that pre-flare activity occurring within the spatial extent of a stable flux rope can destabilize it toward eruption. Moreover, sudden transition of the flux rope from the state of slow rise to fast acceleration precisely bifurcated the precursor and the impulsive phases of the flare which points toward a feedback relationship between early CME dynamics and the strength of the large-scale magnetic reconnection.