An MHD avalanche in a multi-threaded coronal loop
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Date
20/01/2016Funder
Grant ID
ST/K000950/1
ST/L005522/1
ST/N000609/1
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Show full item recordAbstract
For the first time, we demonstrate how an MHD avalanche might occur in a multithreaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs to be unstable in order to start an avalanche even when the others are below marginal stability. This has significant implications for coronal heating in that it provides for energy dissipation with a trigger mechanism. The instability of the unstable thread follows the evolution determined in many earlier investigations. However, once one stable thread is disrupted, it coalesces with a neighboring thread and this process disrupts other nearby threads. Coalescence with these disrupted threads then occurs leading to the disruption of yet more threads as the avalanche develops. Magnetic energy is released in discrete bursts as the surrounding stable threads are disrupted. The volume integrated heating, as a function of time, shows short spikes suggesting that the temporal form of the heating is more like that of nanoflares than of constant heating.
Citation
Hood , A W , Cargill , P , Browning , P & Tam , K 2016 , ' An MHD avalanche in a multi-threaded coronal loop ' , Astrophysical Journal , vol. 817 , no. 1 , 5 , pp. 1-7 . https://doi.org/10.3847/0004-637X/817/1/5
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
Copyright © 2016, American Physical Society. This work is made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://dx.doi.org/10.3847/0004-637X/817/1/5
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We acknowledge the financial support of STFC through the Consolidated grants to the University of St Andrews and the University of Manchester.Collections
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