Surface density of candidate satellites (filled circles) as a function of radius. The full line is the surface density of satellites after accounting for position interlopers. The dotted line indicates the surface density radial slope of a NFW halo. The full and open triangles represent the surface density of satellites found by Sales et al. (2005) and Chen et al. (2006), respectively. The dashed lines show the estimate of the interlopers velocity for μ = 3 × 10^-7 kpc^-2 and μ = 10^-6 kpc^-2.