Simulating Ellerman bomb-like events

2017 
Context. Ellerman bombs (EB) seem to be a part of a whole spectrum of phenomena that might have the same underlying physical mechanism: magnetic reconnection. Aims. The aim of this study is to investigate whether the proposed mechanism, applied to the circumstances of EBs, produces the observed characteristics. Methods. To this end, comprehensive three-dimensional magnetohydrodynamic (3D MHD) simulations were used. Two different cases are presented: the quiet Sun and an active region. Results. Both runs confirm that EB-like brightenings coincide with hot and dense plasma, which is in agreement with predictions of 1D and 2D modellings. The simulated EB-like phenomena assume the observed flame-like form which depends on the complexity of the ongoing reconnection and the viewing angle. At the layers sampled by Hα -wings, near temperature minimum and below, the magnetic field topology seems always to be the same. The field lines there trace the base of the current sheet and the reconnected Ω-loops. Conclusions. The EB features are caused by reconnection of strong-field patches of opposite polarity in the regions where the surface flows are the strongest. The weakest cases among them can be reproduced quantitatively by the current simulations.
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