NGC 4636 Jeans models the blue GCs (final sample) where the dark matter component is represented by a logarithmic potential Eq. (16). Left: models for a mild tangential bias with β =  −0.5. Right: isotropic models (β = 0). In both panels, the best-fit solution is marked by a cross, and the thick solid, dashed and thin solid lines show the 68, 90, and 99 per cent contour levels, respectively. The parameters of the halos shown here are also listed in Table 9.