Figure 16
Figure 16: Total number of black holes ejected in building up to a 1000 M ⊙ IMBH as a function of seed mass. The four numbered curves are made assuming different cluster escape velocities. The dotted line is 103 black holes, the assumed population for a young cluster. As can be seen, a very large seed mass is necessary before IMBH formation by merging black holes becomes a possibility. Image reproduced by permission from Gültekin et al. [186], copyright by IOP.