Secondary Rayleigh-Taylor type Instabilities in the Reconnection Exhaust Jet as a Mechanism for Supra-Arcade Downflows

Abstract

Supra-arcade downflows (hereafter referred to as SADs) are low-emission, elongated, finger-like features usually observed in active-region coronae above post-eruption flare arcades. Observations exhibit downward moving SADs intertwined with bright upward moving spikes. Whereas SADs are dark voids, spikes are brighter, denser structures. Although SADs have been observed for decades, the mechanism of formation of SADs remains an open issue. In our three-dimensional resistive magnetohydrodynamic simulations, we demonstrate that secondary Rayleigh-Taylor type instabilities develop in the downstream region of a reconnecting current sheet. The instability results in the formation of low-density coherent structures that resemble SADs, and high-density structures that appear to be spike-like. Comparison between the simulation results and observations suggests that secondary Rayleigh-Taylor type instabilities in the exhaust of reconnecting current sheets provide a plausible mechanism for observed SADs and spikes.

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Cited by in corpus (22)

• Observations of Turbulent Magnetic Reconnection Within a Solar Current Sheet
• Iris si iv line profiles: An indication for the plasmoid instability during small-scale magnetic reconnection on the sun
• The Origin of Underdense Plasma Downflows Associated with Magnetic Reconnection in Solar Flares
• Blob formation and ejection in coronal jets due to the plasmoid and Kelvin-Helmholtz instabilities
• Plasma Heating Induced by Tadpole-Like Downflows in the Flaring Solar Corona
• The Non-Linear Growth of the Magnetic Rayleigh-Taylor Instability
• Thermodynamical Evolution of Supra-Arcade Downflows
• Generation of turbulence in colliding reconnection jets
• Fractal Reconnection in Solar and Stellar Environments
• Reconnection in the Post-Impulsive Phase of Solar Flares
• Thermodynamics of supra-arcade downflows in solar flares
• Numerical Study on Excitation of Turbulence and Oscillation in Above-the-loop-top Region of a Solar Flare
• Evidence for Vortex Shedding in the Sun's Hot Corona
• Annihilation of Magnetic Islands at the Top of Solar Flare Loops
• Thermodynamic Evolution of Solar Flare Supra-arcade Downflows
• Transition-region explosive events produced by plasmoid instability
• Investigation on the Spatiotemporal Structures of Supra-Arcade Spikes
• MHD simulations of coronal supra-arcade downflows including anisotropic thermal conduction
• Statistical Investigation of the Kinematic and Thermal Properties of Supra-arcade Downflows Observed During a Solar Flare
• Effects of supra-arcade downflows interacting with the post-flare arcade
• Statistical Investigation of the Widths of Supra-arcade Downflows Observed During a Solar Flare
• Numerical MHD simulations of solar flares and their associated small-scale structures