Figure 16

Figure 16: Centripetal acceleration as a function of radius and surface density (color coding as per Figure 14). The critical acceleration a0 is denoted by the dotted line. Milgrom’s formula predicts that acceleration should decline with baryonic surface density, as observed. Moreover, high–surface-density galaxies transition from the Newtonian regime at small radii to the weak-field regime at large radii, whereas low–surface-density galaxies fall entirely in the regime of low acceleration a < a0, as anticipated by Milgrom [294].