Upper panel: best 2D Gaussian fit over-plotted on the SZ map (left), the X-ray surface brightness map (middle) and the optical over-density map (right). The position of the major axis is indicated by the dashed line. The sizes of the ellipses correspond to the 2D Gaussian FWHM. Bottom panel: confidence contours of the position angle and ellipticities, for the SZ image (left, blue), the X-ray map (middle, red) and the galaxy density (right, black). The crosses indicate the best-fit parameters.