Velocities of Flare Kernels and the Mapping Norm of Field Line Connectivity
| Autor: | Alena Zemanová, Elena Dzifčáková, Jaroslav Dudík, Guillaume Aulanier, Juraj Lörinčík |
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| Přispěvatelé: | Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
010504 meteorology & atmospheric sciences
Field line FOS: Physical sciences Geometry 01 natural sciences law.invention Protein filament law 0103 physical sciences Ribbon Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences Physics Solar flare Astronomy and Astrophysics Magnetic reconnection Magnetic field Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Physics::Space Physics Magnetohydrodynamics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Flare |
| Zdroj: | The Astrophysical Journal The Astrophysical Journal, American Astronomical Society, 2019, 881 (1), pp.68. ⟨10.3847/1538-4357/ab298f⟩ |
| ISSN: | 0004-637X 1538-4357 |
| Popis: | We report on observations of flare ribbon kernels during the 2012 August 31 filament eruption. In the 1600\,\AA{} and 304\,\AA{} channels of the Atmospheric Imaging Assembly, flare kernels were observed to move along flare ribbons at velocities $v_\parallel$ of up to $450$ km\,s$^{-1}$. Kernel velocities were found to be roughly anti-correlated with strength of the magnetic field. Apparent slipping motion of flare loops was observed in the 131\,\AA{} only for the slowest kernels moving through strong-$B$ region. In order to interpret the observed relation between $B_{\text{LOS}}$ and $v_\parallel$, we examined distribution of the norm $N$, a quantity closely related to the slippage velocity. We then calculated the norm $N$ of the quasi-separatrix layers (QSLs) in MHD model of a solar eruption adapted to the magnetic environment which qualitatively agrees to that of the observed event. We found that both the modelled $N$ and velocities of kernels reach their highest values in the same weak-field regions, one located in the curved part of the ribbon hook and the other in the straight part of the conjugate ribbon located close to a parasitic polarity. Oppositely, lower values of the kernel velocities are seen at the tip of the ribbon hook, where the modelled $N$ is low. Since the modelled distribution of $N$ matches the observed dynamics of kernels, this supports that the kernel motions can be interpreted as a signature of QSL reconnection during the eruption. |
| Databáze: | OpenAIRE |
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