Intermediate-Mass Black Holes in Globular Cluster Systems

TL;DR

This paper proposes using the ngVLA to survey globular clusters within 25 Mpc to identify intermediate-mass black holes, which could shed light on early universe seed black hole formation and gravitational wave event predictions.

Contribution

It introduces a comprehensive observational strategy with the ngVLA to detect IMBHs in globular clusters, expanding the search to hundreds of systems.

Findings

Potential to validate seed black hole formation channels.

Estimates of IMBH retention rates in globular clusters.

Implications for gravitational wave event predictions.

Abstract

Using the Next Generation Very Large Array (ngVLA), we will make a comprehensive inventory of intermediate-mass black holes (IMBHs) in hundreds of globular cluster systems out to a distance of 25 Mpc. IMBHs have masses of about 100 to 100,000 solar masses. Finding them in globular clusters would validate a formation channel for seed black holes in the early universe and inform event predictions for gravitational wave facilities. Reaching a large number of globular clusters is key, as Fragione et al. (2018) predict that only a few percent will have retained their gravitational-wave fostering IMBHs.