Stacked images with polarimetry information for all involved epochs from early 2007.1 until mid 2012.5. We first stack the maps of the channels Q and U and then combine those to derive the shown maps. Panel a: color-coded distribution of the polarized intensity with overlaid EVPAs on top of total intensity contours in gray. White contours correspond to the polarized intensity. Panel b: distribution of the degree of polarization and overlaid Gaussian (total intensity) model components color-coded for components occurring before and after 2010.3 in orange and blue, respectively.