The polarized emission in the 85 cm RM cube in units of mJy beam^-1 RMSF^-1. From left to right, the situation at decreasing values of right ascension is presented. The right ascension value is reported in the upper left corner of each panel. At RA = 17^h13^m29^s three polarized components are detected, nominally the cluster emission (“cluster”) and the two Galactic Faraday screens (GF1 and GF2). These two components are the only ones detected at the other right ascensions. The emission at location Dec = +64°02′43″ and extending in Faraday depth between –70 rad m^-2 to +100 rad m^-2 comes from the Double radio galaxy.