Left: number density profiles with their best-fit NFW models for red member galaxies (red triangles, solid curve) and all members (black circles, dashed curve), respectively. We obtained reduced χ² = 1.03,2.24 for the red and all member galaxies, which indicates that the red galaxies follow well the theoretical profile and the blue galaxies may account for the deviation of the fit for all member galaxies. The bin size is 300 kpc. Right: ratio of blue to all member galaxies as a function of projection distance from the X-ray flux-weighted centroid. The vertical line remarks .