Pulsar Timing Array Observations of Massive Black Hole Binaries

TL;DR

This paper demonstrates that pulsar timing arrays can accurately detect and characterize individual massive black hole binaries, including their mass, distance, and sky location, by incorporating pulsar distances into the analysis.

Contribution

The study introduces a novel analysis method that includes pulsar distances as parameters, enhancing the detection and parameter estimation of black hole binaries.

Findings

Improved sky localization by an order of magnitude.

Doubling of gravitational wave signal power.

Accurate recovery of binary mass and distance.

Abstract

Pulsar timing is a promising technique for detecting low frequency sources of gravitational waves. Historically the focus has been on the detection of diffuse stochastic backgrounds, such as those formed from the superposition of weak signals from a population of binary black holes. More recently, attention has turned to members of the binary population that are nearer and brighter, which stand out from the crowd and can be individually resolved. Here we show that the timing data from an array of pulsars can be used to recover the physical parameters describing an individual black hole binary to good accuracy, even for moderately strong signals. A novel aspect of our analysis is that we include the distance to each pulsar as a search parameter, which allows us to utilize the full gravitational wave signal. This doubles the signal power, improves the sky location determination by an order of magnitude, and allows us to extract the mass and the distance to the black hole binary.