Probing supermassive black hole mergers and stalling with pulsar timing arrays

TL;DR

This paper discusses how pulsar timing arrays can detect low-frequency gravitational waves from supermassive black hole mergers, providing insights into galaxy evolution, black hole growth, and potential new physics.

Contribution

It highlights the potential of pulsar timing arrays to probe supermassive black hole mergers and stalling, offering a new observational approach for understanding galaxy and black hole evolution.

Findings

Pulsar timing arrays can detect gravitational waves from supermassive black hole mergers.

Detection can inform galaxy merger rates and black hole mass distributions.

Potential to discover new physics at nanohertz gravitational-wave frequencies.

Abstract

The observation of gravitational-waves from merging supermassive black holes will be transformative: the detection of a low-frequency gravitational-wave background can tell us if and how supermassive black holes merge, inform our knowledge of galaxy merger rates and supermassive black hole masses, and enable the possibility of detecting new physics at nanohertz frequencies. All we have to do is time pulsars.