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C. Z. Cheng, G. S. Choe, Y. Ren (Princeton Plasma Physics Laboratory, Princeton University), J. Qiu (NJIT/BBSO), Y. J. Moon (Korea Astronomy Observatory)
MHD simulations of flux rope motion and magnetic reconnection are presented. In particular, we discuss the role of nonuniform anomalous resistivity on the time scale of flux rope acceleration and reconnection rate. The simulation results show that the flux rope's accelerated rising motion is associated with an enhanced magnetic reconnection rate and thus an enhanced reconnection electric field in the current sheet during the flare rise phase. By choosing a particular dependence of resistivity on the current density, the simulation results are in good quantitative agreement with the observed temporal profile of the filament-CME acceleration. Moreover, the impulsive rise of the magnetic reconnection rate obtained from the simulations are also in good quantitative agreement with those obtained from the magnetogram data and horizontally expanding two-ribbon emissions for CME-flare events. For the X-class flare events the peak reconnection electric field is ~O(103 V/m) or larger, enough to accelerate electrons to over 100 keV in a field-aligned distance of 0.1 km and produce an impulsive hard X-ray emission observed during the flare rise phase. Thus, the simulation results are consistent with CME-flare events that show a temporal correlation among the peak filament-CME acceleration, the impulsive flare non-thermal emissions, and the peak rate of GOES X-ray emission. We will discuss the implications of the empirical anomalous resistivity model on the microscopic reconnection and particle acceleration processes in the current sheet.
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Bulletin of the American Astronomical Society, 36 #2
© YEAR. The American Astronomical Soceity.