Vortex and sink flows in eruptive flares as a model for coronal implosions

Abstract

Eruptive flares are sudden releases of magnetic energy that involve many phenomena, several of which can be explained by the standard 2D flare model and its realizations in three-dimensions. We analyze a three-dimensional magnetohydrodynamics simulation in the framework of this model that naturally explains the contraction of coronal loops in the proximity of the flare sites, as well as the inflow towards the region above the cusp-shaped loops. We find that two vorticity arcs located along the flanks of the erupting magnetic flux rope are generated as soon as the eruption begins. The magnetic arcades above the flux-rope legs are then subjected to expansion, rotation or contraction depending on which part of the vortex-flow advects them. In addition to the vortices, an inward-directed magnetic pressure gradient exists in the current sheet below the magnetic flux rope. It results in the formation of a sink that is maintained by reconnection. We conclude that coronal loop apparent implosions observed during eruptive flares are the result of hydro-magnetic effects related to the generation of vortex- and sink-flows when a flux rope moves in a magnetized environment.

14 pages, 9 figures, to appear in The Astrophysical Journal

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Cited by in corpus (5)

• Observation of all pre- and post-reconnection structures involved in three-dimensional reconnection geometries in solar eruptions
• Flare reconnection-driven magnetic field and Lorentz force variations at the Sun's surface
• Observations of a prominence eruption and loop contraction
• Simulating coronal loop implosion and compressible wave modes in a flare hit active region
• The Causes of Peripheral Coronal Loop Contraction and Disappearance Revealed in a Magnetohydrodynamic Simulation of Solar Eruption