ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
tokens: in changing our results. We stop our pure infall models earlier than , as these runs require much more computing time than our standard runs. However, this should not greatly affect our analysis, as the behaviour of these runs is clear and is unlikely to change significantly in the period between t final and 1000 yr. In the pure infall realizations only one sink forms and grows rapidly via accretion, reaching a mass of over in only ∼100 yr. In contrast, all of the other runs show considerable fragmentation within the first 1000 yr, forming anywhere between 15 and ∼120 sinks. The total mass in sinks (M tot ) and the total number of sinks (N tot ) in each realization at the final output time is listed in Table 3, and time evolution of these quantities is shown in Figs 2 and 3 , respectively. In addition, Fig. 4 shows some illustrative examples of the evolution of some of our realizations. The difference in behaviour that we see between the pure infall runs and the other runs occurs because the pure infall runs are the only ones in which no disc forms over the course of the simulations. Some non-zero angular momentum arises during the gravitational collapse but is too small to trigger the formation of a disc. In all of the other runs 3 a dense, gravitationally unstable accretion disc forms which soon fragments. Figure 2. Total mass in sinks as a function of time after the first sink is created. Each panel shows the results for the five different realizations of each setup. Increasing the initial turbulent or rotational energy tends to systematically decrease the total mass in sinks at any given time. We also see that there is significant variation from simulation to simulation for all of the setups with non-zero initial turbulence, but not for the setups with non-initial turbulence. Figure 3. Total number of sinks as a function of the time elapsed after the formation of the first sink. The colour scheme is the same as in Fig. 2 . We see that the number of sinks that form varies substantially from simulation to simulation for all of the setups. A colour version is available online. Figure 4. Column density plots (two top rows: x – y plane of the simulation box; two bottom rows: x – z plane of the simulation box) of the evolution of realization β01 – 1, α005 – 5, and α025β001 – 3. In the purely rotational runs, the protostellar disc lies in the geometrical x – y plane of our simulation box during the whole of the simulation, as demonstrated here for run β01 – 1. In all runs including turbulence, however, the orientation of the disc varies strongly over time. The projections are centred on the centre of mass of both sink particles and gas within a 500 AU radius around the most massive sink particle at the time of the snapshot considered. The projection thickness is about half the size of our simulation box (), the distance between the position of the first sink and the edge of the simulation box. In our plots of the evolution of the total mass