Returning magnetic flux in sunspot penumbrae

Abstract

Aims: We study the presence of reversed polarity magnetic flux in sunspot penumbra.
Methods: We applied a new regularized method to deconvolve spectropolarimetric data observed with the spectropolarimeter SP onboard Hinode. The new regularization is based on a principal component decomposition of the Stokes profiles. The resulting Stokes profiles were inverted to infer the magnetic field vector using SIR.
Results: We find, for the first time, reversed polarity fields at the border of many bright penumbral filaments in the whole penumbra.