Radial velocity versus galactocentric distance for blue GCs with velocity uncertainties Δv < 50   km   s^-1. The curves, calculated from Eq. (17) for the total mass as given in model B.iso (Table 9 NFW halo), indicate pericentric velocities for fixed apocentric distances. Objects outside a given line have apocentric distances of at least the value for which the curve was calculated.