Simulation of dark lanes in post-flare supra-arcade

Authors

  • A. Costa,

    Corresponding author
    1. Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Laprida 854, X5000 BGR, Córdoba, Argentina
    2. Instituto de Astronomía Teórica y Experimental, 5000, Córdoba, Argentina
    3. Consejo Nacional de Investigaciones Científicas y Técnicas C1033 AAJ, Buenos Aires, Argentina
    Search for more papers by this author
  • S. Elaskar,

    1. Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Laprida 854, X5000 BGR, Córdoba, Argentina
    2. Consejo Nacional de Investigaciones Científicas y Técnicas C1033 AAJ, Buenos Aires, Argentina
    Search for more papers by this author
  • C. A. Fernández,

    1. Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Laprida 854, X5000 BGR, Córdoba, Argentina
    Search for more papers by this author
  • G. Martínez

    1. Instituto de Astronomía y Física del Espacio, 1428, Buenos Aires, Argentina
    Search for more papers by this author

E-mail: acosta@mail.oac.uncor.edu

ABSTRACT

We integrate the magnetohydrodynamics (MHD) ideal equations to simulate dark void sunwardly moving structures in post-flare supra-arcades. We study the onset and evolution of the internal plasma instability to compare with observations and to gain insight into physical processes and characteristic parameters of these phenomena. The numerical approach uses a finite-volume Harten–Yee total variation diminishing (TVD) scheme to integrate the 1D 1/2 MHD equations specially designed to capture supersonic flow discontinuities. The integration is performed in both directions, the sunward radial one and the transverse to the magnetic field. For the first time, we numerically reproduce observational dark voids described in Verwichte et al. We show that the dark tracks are plasma vacuums generated by the bouncing and interfering of shocks and expansion waves, upstream an initial slow magnetoacoustic shock produced by a localized deposition of energy modelled with a pressure perturbation. The same pressure perturbation produces a transverse to the field or perpendicular magnetic shock giving rise to non-linear waves that compose the kink-like plasma void structures, with the same functional sunward decreasing phase speed and constancy with height of the period, as those determined by the observations.

Ancillary