King Models

(Left) Density profiles for four King models, with decreasing concentration top to bottom (smaller tidal ratio, rt/r0). Upper is the 3-d space density; lower is the projected density. (Right; Upper): two measures of the concentration plotted against each other, the tidal radius rt/r0 against the ratio of the potential at r=0 to the velocity dispersion (larger tidal radii have deeper central potentials). (Right; Lower): velocity dispersion profiles (dotted is projected, los) for the four King models. Note, they are constant out to near the tidal radius, where they fall down (as required, so that stars near the tidal radius have zero velocity).