Probing globular clusters using modulated gravitational waves from binary black holes

TL;DR

This paper introduces a novel gravitational wave-based method using binary black holes within globular clusters to improve the accuracy of measuring cluster distances and masses, surpassing traditional electromagnetic techniques.

Contribution

It proposes a new approach leveraging GW modulations from BBHs in GCs to enhance parameter estimation accuracy beyond existing electromagnetic methods.

Findings

GW observations can reduce uncertainties in GC distance measurements by an order of magnitude.

Modulated GW signals encode detailed information about the host globular cluster.

The method demonstrates significant potential for advancing stellar dynamics studies.

Abstract

Globular clusters (GCs) are crucial for studying stellar dynamics and galactic structure, yet precise measurements of their distances and masses are often limited by uncertainties in electromagnetic (EM) observations. We present a novel method that leverages gravitational waves (GWs) from stellar-mass binary black holes (BBHs) orbiting within GCs to enhance the precision of GC parameter measurements. The BBH's orbital motion imprints characteristic modulations on the GW waveform, encoding information about the host GC. Using post-Newtonian waveforms and Lorentz transformations, we simulate modulated GW signals and evaluate the resulting parameter constraints via a Fisher information matrix analysis. Our results show that incorporating GW observations can significantly reduce the uncertainties in GC distance and mass measurements, in many cases achieving improvements by an order of magnitude. These findings demonstrate the value of BBHs as dynamical probes and highlight the power of GWs to advance GC studies beyond the limits of traditional EM methods.