An investigation of loop-type CMEs with a 3D MHD simulation

CMEs have erupted filaments (core) and flux loops that lie over the filament (leading edge) and a cavity between the core and leading edge. In one model "Flux loops are pushed up by erupted filaments and expand upwards" which roughly explains much about CMEs. But there are some CMEs with characteristics that are inexplicable with this model, which have a twisted structure along the loop and the structure of a convex lens at the loop top (Illing and Hundhausen 2000). We consider Torsional Alfven Wave (TAW) propagation as the cause of these characteristics for some CMEs, and have studied this with a 3D MHD simulation. As a result, we found that TAW propagation most likely explains these characteristics for some CMEs and that a TAW can carry out plasma from the chromosphere to coronal space along the loop. We propose a new scenario about the occurrence of CMEs based on results of our simulation and observations.