Study of Magnetic Tongues Properties in Solar Active Regions

POISSON, M.; LOPEZ FUENTES, M.; MANDRINI, C.H.; DÉMOULIN, P.

Mar del Plata

Congreso; 55 Reunión Anual de la Asociación Argentina de Astronomía; 2012

Asociación Argentina de Astronomía

We study the emergence of solar active regions (ARs) to determine how their magnetic helicity properties affect the evolution of the photospheric flux observed in line of sight magnetograms. We characterize the so called magnetic tongues, which are projection effect in twisted emerging flux-tubes that form ARs. We determine and study the evolution of a series of parameters, such as the tilt angle, the polarity inversion line orientation (PIL), the magnetic flux, the size and the shape of the polarities and their tongues for 25 ARs observed between 2004 and 2010. We compute a model for a toroidal flux tube emergence with different amounts of twist and we test several methods for measuring the PIL. Finally we obtain a good aproximation of the PIL evolution and we were able to infer the sign of the twist by comparing the results with our model predictions.