Spectroscopic Signatures of Plasma-Sheet Dynamics in a Solar Flare
Abstract
According to the standard eruptive flare model, energy is released in a current sheet formed in the wake of an erupting flux rope. The current sheet itself is theoretically predicted to be 10m wide, thus representing a significant challenge for current observational techniques. However, a handful of observations have reported enhanced emission from the region surrounding the current sheet, often referred to as the plasma-sheet. Since this region must respond to processes occurring in the current sheet itself, the study of its properties offers the possibility to indirectly probe conditions in the current sheet related to the reconnection process. Recent observations (Warren al., (2018), Li et al., 2018) have demonstrated the presence of enhanced nonthermal velocities in the current sheet observed in the 10th September 2017 X8.2 class flare, consistent with the presence of turbulence and possible tearing mode instability. In this study, we combine observations from the Extreme-ultraviolet Imaging Spectrometer (EIS) and Atmospheric Imaging Assembly (AIA) to explore the relationship between the Alfven speed calculated for different plasma beta regimes, observed non-thermal velocity measurements, and the evolution of the plasma-sheet to test for the presence of the plasmoid instability.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2019)
- Pub Date:
- May 2019
- Bibcode:
- 2019shin.confE.186F