English

3D MHD simulation of flare supra-arcade downflows in a turbulent current sheet medium

Solar and Stellar Astrophysics 2015-05-12 v2

Abstract

Supra-arcade downflows (SADs) are sunward, generally dark, plasma density depletions originated above posteruption flare arcades. In this paper using 3D MHD simulations we investigate if the SAD cavities can be produced by a direct combination of the tearing mode and Kelvin-Helmholtz instabilities leading to a turbulent current sheet (CS) medium or if the current sheet is merely the background where SADs are produced triggered by an impulsive deposition of energy. We find that to give account of the observational dark lane structures an addition of local energy, provided by a reconnection event, is required. We suggest that there may be a closed relation between characteristic SAD sizes and CS widths that must be satisfied to obtain an observable SAD.

Keywords

Cite

@article{arxiv.1407.3298,
  title  = {3D MHD simulation of flare supra-arcade downflows in a turbulent current sheet medium},
  author = {M. Cécere and E. Zurbriggen and A. Costa and M. Schneiter},
  journal= {arXiv preprint arXiv:1407.3298},
  year   = {2015}
}

Comments

12 pages, 10 figures. Accepted for publication in The Astrophysical Journal