Probing Stellar Dynamics in Galactic Nuclei

TL;DR

Future low-frequency gravitational wave observations will significantly enhance our understanding of supermassive black holes and stellar dynamics in galactic nuclei by providing precise measurements and revealing otherwise hidden stellar remnants.

Contribution

This paper highlights the potential of upcoming gravitational wave observations to probe SMBH properties and stellar populations in galactic centers, complementing electromagnetic data.

Findings

Gravitational waves in the 10^{-5}-10^{-1} Hz range can measure SMBH masses and spins with high precision.

Such observations can detect stellar remnants in galactic centers that are otherwise invisible.

Combining gravitational wave and electromagnetic data offers new insights into SMBH-environment interactions.

Abstract

Electromagnetic observations over the last 15 years have yielded a growing appreciation for the importance of supermassive black holes (SMBH) to the evolution of galaxies, and for the intricacies of dynamical interactions in our own Galactic center. Here we show that future low-frequency gravitational wave observations, alone or in combination with electromagnetic data, will open up unique windows to these processes. In particular, gravitational wave detections in the 10^{-5}-10^{-1} Hz range will yield SMBH masses and spins to unprecedented precision and will provide clues to the properties of the otherwise undetectable stellar remnants expected to populate the centers of galaxies. Such observations are therefore keys to understanding the interplay between SMBHs and their environments.