Same as Fig. 2, but with a zoom into the densest region. Computed slopes (and their errors) for both the targeted C complex asteroids and ground-based average spectrum of Ceres are overplotted with green and dark gray boxes, respectively. The median slope value of the surface of Ceres are represented by a blue cross. The black, blue, and green contours correspond to the 99.7%, 95%, and 68% most usual values, i.e., 3σ, 2σ, and 1σ distance to the median.