Point-to-point I_R /I_X correlation for A2061. Top panel: colour scale is the XMM-Newton surface-brightness smoothed image, after subtraction of point sources. Radio contours at 144 MHz (80″ resolution) are shown in purple. The regions used to extract the surface brightness for the I_R/I_X correlation are 80″ wide boxes. The green boxes cover the entire object, while magenta boxes are only over the radio emission beyond the X-ray plume. Bottom panel: radio/X-ray surface-brightness correlation. The solid green line indicates the best-fit power-law relation for the green points. The slope of the green correlation is reported in the top right corner. The magenta points, relative to the NE extension, show no correlation.