Comparison between the location of the reverse shock as seen in the radio and as probed by interior non-thermal X-rays. Leftis Fig. 3 (top right). Right is a hardness ratio map with the bright parts likely indicating where non-thermal emission is dominant. The location of the reverse shock as implied from the radio map (white circle) does not match the location as seen from non-thermal X-ray filaments (cyan circle). The white dot is the expansion centre as found in Thorstensen et al. (2001).