Variation of the location (left panels) and amplitude (right panels) of the rest-mass density maximum over β_c for different angular momentum profiles and q. Top panels: power-law distribution. The thick line shows the constant case, the dashed line presents model 3, the dotted line model 2, and the dot-dashed line model 1 in Fig. 1. Bottom panels: trigonometric profiles of angular momentum in different colours. The dotted line represents q = 0, the solid line q = −0.4, the dashed line q = −0.2, the crossed line q = 0.8, and the dot-dashed line q = 1.5.