Self-gravitating simulations of N=30 000 particles with different bulk densities. Simulations continue from the ringlet stage (at T = 10 000) of the nongravitating simulation of Fig. 9 with µ = 0.1, R = 0.0005 (100 m in Chariklo’s case): the snapshot of the initial state is shown in the upper left frame. The other frames display self-gravitating simulations with ρ= 300, 450, and 900 kg m⁻³, corresponding to r_h = 1.0, 1.15, and 1.44, respectively at the distance of the 1/3 SOR. Times are counted from the beginning of the self-gravitating simulation. The upper right frame displays the evolution of the ringlet mean width, $W=\sqrt{12\langle {\left(r-r_{\text{fit}}\right)}^2\rangle }$, where r_fit denotes the fitted ringlet central line at the azimuth of the particle and the averaging is over all particles (for a uniform particle distribution this formula with the factor of 12 recovers the full width of the ringlet). The remaining frames on the right show the semimajor axis distribution at different instants for the three self-gravitating runs.