On the polarimetric signature of emerging magnetic loops in the quiet-Sun

Abstract

The abundance of Stokes V profiles dominated by one lobe at the locations of emergence of Omega-shaped magnetic loops is evaluated. The emergence events were found in Hinode SOT/SP time-sequences of quiet-Sun regions. Such a study has the aim of confirming a prediction based on the basic geometrical and physical properties of emerging magnetic loops: Stokes V profiles dominated by one lobe are possibly the main polarimetric signature of these structures. In agreement with this prediction, 47 % of the Stokes V profiles analyzed has an unsigned amplitude asymmetry larger than 0.3, while in the quiet-Sun the abundance is of about 30 %. This excess with respect to the quiet-Sun is found consistently for whatever value of the threshold on the amplitude asymmetry. Such a result proves the goodness of the physical scenarios so far proposed for the interpretation of loop emergence events and may prompt the use of Stokes V profiles dominated by one lobe as a new proxy for their identification in observations with a good spectral sampling.