The interaction between supermassive black holes and globular clusters

TL;DR

This study uses N-body simulations to explore how supermassive black holes influence the survival and formation of nuclear star clusters in galaxies, revealing an upper mass limit for SMBHs that prevents NSC formation.

Contribution

It provides the first high-resolution simulation-based analysis of the impact of SMBHs on globular cluster dynamics and NSC formation in galaxies.

Findings

Identified an upper SMBH mass limit for NSC formation.

Showed SMBH tidal forces can disrupt infalling globular clusters.

Linked galaxy mass to the likelihood of hosting a nuclear star cluster.

Abstract

Almost all galaxies along the Hubble sequence host a compact massive object (CMO) in their center. The CMO can be either a supermassive black hole (SMBH) or a very dense stellar cluster, also known as nuclear star cluster (NSC). Generally, heavier galaxies (mass $\gtrsim 10^{11}\mathrm{M}_{\odot}$ ) host a central SMBH while lighter show a central NSC. Intermediate mass hosts, instead, contain both a NSC and a SMBH. One possible formation mechanisms of a NSC relies on the dry-merger (migratory) scenario, in which globular clusters (GCs) decay toward the center of the host galaxy and merge. In this framework, the absence of NSCs in high-mass galaxies can be imputed to destruction of the infalling GCs by the intense tidal field of the central SMBH. In this work, we report preliminary results of N-body simulations performed using our high-resolution, direct, code HiGPUs, to investigate the effects of a central SMBH on a single GC orbiting around it. By varying either the mass of the SMBH and the mass of the host galaxy, we derived an upper limit to the mass of the central SMBH, and thus to the mass of the host, above which the formation of a NSC is suppressed.