Forecasting the sensitivity of Pulsar Timing Arrays to gravitational wave backgrounds

TL;DR

This paper develops a framework to predict how well future Pulsar Timing Arrays can detect and analyze the gravitational wave background, aiding the understanding of astrophysical and cosmological sources.

Contribution

It introduces a simple, adaptable framework and provides a Python tool for forecasting PTA sensitivity and parameter estimation of the SGWB.

Findings

Framework enables sensitivity forecasts for future PTAs

Python code fastPTA available for community use

Assesses potential to distinguish multiple SGWB contributions

Abstract

Pulsar Timing Array (PTA) observations hinted towards the existence of a stochastic gravitational wave background (SGWB) in the nHz frequency band. Still, the nature of the SGWB signal cannot be confidently inferred from current data, and the leading explanation invokes mergers of supermassive black holes. If confirmed, such discovery would not only represent a turning point in our understanding of astrophysics, but it may severely limit the capability of searching for additional cosmological sources in the nHz frequency range. In this work, we build a simple framework to forecast the sensitivity of future PTA configurations and assess the parameter estimation of SGWB, which could consist of several contributions. We release the python code fastPTA implementing this framework and ready to use.