Surface-brightness profiles of A 2142 obtained with different methods. The data points show the spectroscopic measurements (red), the azimuthally averaged profile (blue), and the azimuthal median (green). The green and blue thin dashed lines show the corresponding best fits obtained with the multiscale deprojection method. The solid and dashed horizontal lines correspond to the total background level and to the uncertainty on the background, respectively. The dashed and dash-dotted vertical lines represent R₅₀₀ and R₂₀₀, respectively.