How black holes shape globular clusters: Modeling NGC 3201

TL;DR

This study uses Monte Carlo simulations to model the globular cluster NGC 3201, revealing it likely hosts over 200 stellar-mass black holes and predicting the formation of specific binary systems, enhancing understanding of black hole impacts on cluster evolution.

Contribution

The paper introduces detailed Monte Carlo models of NGC 3201 that match observations and predict black hole populations and binary formations not previously confirmed.

Findings

NGC 3201 likely contains over 200 stellar-mass black holes.

Formation of main sequence-BH binaries similar to observed systems.

Existence of bright blue-straggler-BH binaries in core-collapsed clusters.

Abstract

Numerical simulations have shown that black holes (BHs) can strongly influence the evolution and present-day observational properties of globular clusters (GCs). Using a Monte Carlo code, we construct GC models that match the Milky Way (MW) cluster NGC 3201, the first cluster in which a stellar-mass BH was identified through radial-velocity measurements. We predict that NGC 3201 contains $\gtrsim 200$ stellar-mass BHs. Furthermore, we explore the dynamical formation of main sequence-BH binaries and demonstrate that systems similar to the observed BH binary in NGC 3201 are produced naturally. Additionally, our models predict the existence of bright blue-straggler-BH binaries unique to core-collapsed clusters, which otherwise retain few BHs.