corresponding core-halo state. The data is averaged over $\d \t=100$ time intervals.](fig7.eps){width=".45\textwidth"}

We observe that if the number of particles is increased but the rescaled energy $\e$ is kept fixed, it takes generally longer time for the collapse to be complete. Our results (see Fig. \[fig\_N\]) qualitatively confirm that the characteristic time for the full collapse scales as $\t_r$ [@bt]. A quantitative study of the dependence of the collapse dynamics on the number of particles requires much faster simulation code, however.

![\[fig\_N\] Collapse in systems with $\e=-0.5$ and different numbers of particles, $N=125$ (dashed line) and $N=250$ (solid line), shown in relaxation time units, $\t\ln N/N$ [@bt]. Horizontal line shows the kinetic energy of the target core-halo state. The data is averaged over $\d \t=100$ time intervals.](fig8.eps){width=".45\textwidth"}

In the above examples, the energy was set to $\e=-0.5$ which is well below $\e_{coll}\approx-0.339$, and as a consequence the collapse started immediately at $\t=0$ in all simulation runs. If the system energy is $\e_{coll}$, the noticeable increase in kinetic energy and decrease of the virial variable, characteristic for collapse, start not exactly at $\t=0$ but with a small delay (Fig. \[fig\_ec1\]) which varies from run to run from almost zero to about 