Transverse SB profile of the filament. Top: configuration of the boxes used to extract a transverse SB profile (yellow). The length of the boxes, 2.3 deg, was set to minimize the contribution from cluster outskirts while retaining most of the filament contribution. The box width is 12 arcmin. The SB background is constrained from both red boxes. The same background boxes are used for the spectral analysis. The cyan box is the combination of the three central yellow boxes and was used as source extraction region for the spectral analysis. Bottom: resulting SB data points with a truncated β-model fit with β = 2/3 and R_max = 60′. Positive distances are toward Bkg S, and negative distances are towards Bkg N.