Magnetic Helicity and Active Filaments
Paolo Romano (INAF — Osservatorio Astrofisico di Catania)
Abstract. Flux ropes (FR) are crucial in many models of the formation and eruption of solar filaments. Taking into account that the presence of FRs is usually accompanied by observations of shearing or rotating motions of magnetic features at the photospheric level and that FRs are characterized by a helical configuration of the magnetic field, it is useful to measure the complexity and instability of the magnetic field by considering the magnetic helicity evolution in corona during the FR lifetime. This talk is dedicated to present the different behavior in the accumulation of the magnetic helicity flux in the corona, depending on the magnetic configuration and on the location of the FR in the ARs. In fact, the complexity and strength of the photospheric magnetic field is only a partial indicator of the real likelihood of an AR producing the eruption of a FR. Moreover, some observations show that the photospheric regions where the filaments are rooted might be the preferential ways where the magnetic helicity is injected along the filament itself during its formation phase and where the magnetic field configuration is modified.
Contributed Talk
