Talk abstract

The CME triggering mechanism in the flux cancellation model
G. Aulanier, T. Török, P. Démoulin, E.E. DeLuca


We conduct and analyze a zero-beta
3D MHD simulation of flux rope formation and
eruption in the corona, in the context of the
'flux cancellation' model. Numerous previously
suggested CME triggering mechanisms are found
to take place in our simulation. We test which
of those actually triggers the eruption, and
which only contribute to the formation and
pre-eruptive evolution of the flux rope. We
find that neither bald-patch reconnection,
nor slip-running tether-cutting reconnection,
nor flux decrease through photospheric
cancellation trigger the eruption. Rather,
the eruption is caused by the ideal MHD torus
instability, after the abovementioned mechanisms
have driven the system towards the point at
which the onset criteria for the instability
are met. We then confront our model to HINODE/XRT
observations of an erupting sigmoid, which results
in new physical interpretations of several
observed features.