A C-level flare observed in an arch filament system: reconnection between pre-existing and emerging field lines?

Context. Observations show that solar flares are often caused by the emergence of new magnetic flux from subphotospheric layers and by the interaction of the rising field lines with the ambient magnetic field. In this framework, recent theoretical models of magnetic flux emergence have investigated the effectiveness of magnetic reconnection as a function of the old and new flux system relative orientations.