Astron. Astrophys. 360, 345-350 (2000)

Magnetic topology during the reconnection process in a kinked coronal loop

H. Baty

Observatoire Astronomique, 11 Rue de l'Université, 67000 Strasbourg, France (baty@astro.u-strasbg.fr)

Received 9 March 2000 / Accepted 6 June 2000

Abstract

The magnetic topology change that arises during the evolution of the kink instability in a solar coronal loop is studied using a three-dimensional MHD simulation in cylindrical geometry. The initial structure is an axisymmetric twisted magnetic flux tube carrying a vanishing axial electric current, that has primarily evolved towards a kinked configuration containing an intense current concentration along the loop. Consequently, the ensuing evolution becomes resistive allowing a stationnary reconnection process to occur (Baty 2000). The system finally reaches a relaxed configuration of lower magnetic energy with three topologically distinct regions. Indeed, the original highly twisted central region is transformed into two interwoven flux tubes with field lines having a small amount of twist within each tube. This first region is surrounded by a weakly non axisymmetric annular flux tube that is embedded into the original potential magnetic field. Using mappings of field lines along the loop from one photospheric end, we draw a schematic description of the magnetic topology change in terms of the initial distributions of the twist and/or of the axial current density.

Key words: instabilities magnetic fields Magnetohydrodynamics (MHD) molecular data Sun: corona

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Contents

• 1. Introduction
• 2. The loop model
• 3. The numerical results
• 4. Conclusion
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: July 27, 2000
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