Observational signatures of the coronal kink instability with thermal conduction

Botha, Gert, Arber, Tony and Srivastava, Abhishek (2012) Observational signatures of the coronal kink instability with thermal conduction. The Astrophysical Journal, 745 (1). p. 53. ISSN 0004-637X

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Official URL: http://dx.doi.org/10.1088/0004-637X/745/1/53

Abstract

It is known from numerical simulations that thermal conduction along magnetic field lines plays an important role in the evolution of the kink instability in coronal loops. This study presents the observational signatures of the kink instability in long coronal loops when parallel thermal conduction is included. The 3D nonlinear magnetohydrodynamic equations are solved numerically to simulate the evolution of a coronal loop that is initially in an unstable equilibrium. The loop has length 80 Mm, width 8 Mm and an initial maximum twist of Φ = 11:5 π, where Φ is a function of the radius. The initial loop parameters are obtained from a highly twisted loop observed in the TRACE 171 A waveband. Synthetic observables are generated from the data. These observables include spatial and temporal averaging to account for the resolution and exposure times of TRACE images. Parallel thermal conduction reduces the maximum local temperature by up to an order of magnitude. This means that different spectral lines are formed and different internal loop structures are visible with or without the inclusion of thermal conduction. However, the response functions sample a broad range of temperatures. The result is that the inclusion of parallel thermal conductivity does not have as large an impact on observational signatures as the order of magnitude reduction in the maximum temperature would suggest; the net effect is a blurring of internal features of the loop structure.

Item Type: Article
Uncontrolled Keywords: instabilities, magnetic fields, magnetohydrodynamics (MHD), Sun: corona
Subjects: F300 Physics
F500 Astronomy
G900 Others in Mathematical and Computing Sciences
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Gert Botha
Date Deposited: 05 Apr 2013 10:11
Last Modified: 15 May 2017 00:15
URI: http://nrl.northumbria.ac.uk/id/eprint/11955

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