Retrieval of the full magnetic vector with the He I multiplet at 1083 nm

Abstract

A technique is presented to invert Stokes profiles of the He I 1083 nm multiplet lines in order to obtain the full magnetic vector and the line-of-sight velocity. The technique makes use of spectropolarimetry connected with the Zeeman effect supplemented by a simple Hanle effect based diagnostic when appropriate. It takes into account effects like line saturation, magnetooptical effects, etc. and is coupled with a genetic algorithm, which ensures that the global minimum in a goodness of fit hypersurface is found. Tests using both artificial and real data demonstrated the robustness of the method. As an illustration maps of deduced parameters of an emerging flux region are shown and briefly discussed.