Simulations predict intermediate-mass black hole formation in globular clusters.

The formation process of intermediate-mass black holes (IMBHs), defined as those between 100 and 10 solar masses (), is debated. One potential origin is the growth of less-massive black holes merging with stars and compact objects within globular clusters (GCs). However, previous simulations have indicated that this process only produces IMBHs under 500 before gravitational wave recoil ejects them from the GC.

The origin of OB runaway stars.

About 20% of all massive stars in the Milky Way have unusually high velocities, the origin of which has puzzled astronomers for half a century. We argue that these velocities originate from strong gravitational interactions between single stars and binaries in the centers of star clusters. The ejecting binary forms naturally during the collapse of a young (≤1 million years old) star cluster.