Massive Black Hole Binaries and Where to Find Them with Dual Detector Networks

TL;DR

This paper investigates how dual space-based gravitational wave detector networks, such as LISA combined with Taiji or TianQin, enhance the localization and parameter estimation of massive black hole binaries.

Contribution

It demonstrates that dual detector networks significantly improve sky localization and parameter estimation for massive black hole binaries compared to a single detector.

Findings

Orders of magnitude improvement in sky localization with dual networks.

Enhanced parameter estimation for lower mass systems.

Significant improvements in distance determination.

Abstract

A single space-based gravitational wave detector will push the boundaries of astronomy and fundamental physics. Having a network of two or more detectors would significantly improve source localization. Here we consider how dual networks of space-based detectors would improve parameter estimation of massive black hole binaries. We consider two scenarios: a network comprised of the Laser Interferometer Space Antenna (LISA) and an additional LISA-like heliocentric detector (e.g. Taiji); and a network comprised of LISA with an an additional geocentric detector (e.g. TianQin). We use Markov chain Monte Carlo techniques and Fisher matrix estimates to explore the impact of a two detector network on sky localization and distance determination. The impact on other source parameters is also studied. With the addition of a Taiji or TianQin, we find orders of magnitude improvements in sky localization for the more massive MBHBs, while also seeing improvements for lower mass systems, and for other source parameters.