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MHD simulations of coronal dark downflows considering thermal conduction

Published online by Cambridge University Press:  12 September 2017

E. Zurbriggen ,
A. Costa ,
A. Esquivel ,
M. Schneiter  and
M. Cécere
E. Zurbriggen
Affiliation:
Instituto de Astronomía Teórica y Experimental, CONICET, Córdoba, Argentina
A. Costa
Affiliation:
Instituto de Astronomía Teórica y Experimental, CONICET, Córdoba, Argentina Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Argentina
A. Esquivel
Affiliation:
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México
M. Schneiter
Affiliation:
Instituto de Astronomía Teórica y Experimental, CONICET, Córdoba, Argentina Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Argentina
M. Cécere
Affiliation:
Instituto de Astronomía Teórica y Experimental, CONICET, Córdoba, Argentina
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Abstract

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While several scenarios have been proposed to explain supra-arcade downflows (SADs) observed descending through turbulent hot regions, none of them have systematically addressed the consideration of thermal conduction. The SADs are known to be voided cavities. Our model assumes that SADs are triggered by bursty localized reconnection events that produce non-linear waves generating the voided cavity. These subdense cavities are sustained in time because they are hotter than their surrounding medium. Due to the low density and large temperature values of the plasma we expect the thermal conduction to be an important process. Our main aim here is to study if it is possible to generate SADs in the framework of our model considering thermal conduction. We carry on 2D MHD simulations including anisotropic thermal conduction, and find that if the magnetic lines envelope the cavities, they can be isolated from the hot environment and be identified as SADs.

Keywords

Sun: coronamagnetic fieldsPhysical Processes: MHDconductioninstabilitiesturbulenceshock waves
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 12 , Symposium S327: Fine Structure and Dynamics of the Solar Atmosphere , October 2016 , pp. 128 - 133
Copyright
Copyright © International Astronomical Union 2017 

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