Abstract Details
| Name: Upendra Kumar Singh Kushwaha Affiliation: Udaipur Solar Observatory, PRL, Udaipur Conference ID: ASI2015_551 Title : Large-scale implosion in coronal loops during the pre-flare phase of an M6.2 flare and associated failed eruption of a filament Authors and Co-Authors : Bhuwan Joshi Udaipur Solar Observatory, PRL,Udaipur-313001, India and Astrid M. Veronig Kanzelhöhe Observatory/Institute of Physics, University of Graz, Universittäsplatz 5, A-8010 Graz, Austria Abstract Type : Oral Abstract Category : Sun and the Solar System Abstract : In this paper, we present a comprehensive multi-wavelength study of an M6.2 flare which was associated with a failed eruption of a filament using TRACE, RHESSI, and NoRH observations. The pre-flare phase of this event is characterized by spectacular large-scale contraction (implosion) of overlying EUV coronal loops during which the loop system was subjected to an altitude decrease of ~20 Mm (40% of the initial height) for an extended span of ~30 min. This contraction phase is accompanied by the sequential brightening in low-lying loops in the core of flaring region which is spatially correlated with HXR (up to 25 keV) and MW sources, indicating the occurrence of localized events of magnetic reconnection in the source region before the prominence eruption and associated M-class flare. With the onset of the impulsive phase of the M6.2 flare, we detect HXR and MW sources that exhibit intricate temporal and spatial evolution in relation with the fast rise of the prominence. Following the flare maximum, the filament eruption slowed down and subsequently confined within the large overlying active region loops; the event did not lead to the coronal mass ejection (CME). During the confinement process of the erupting prominence, we detect MW emission from the extended coronal region with multiple emission centroids which likely represent emission from hot blobs of plasma formed after the collapse of the expanding flux rope and entailing prominence material. RHESSI observations reveal high plasma temperatures (~29–32 MK) and substantial non-thermal characteristics with electron spectral index (δ~5) during the impulsive phase. The evolution of thermal energy correlates nicely with the cumulative integral of non-thermal energy which suggest that the energy of accelerated particles is efficiently converted to heat and kinetic energy of localized flaring plasma showing the effective validation of the ‘Neupert effect’. |