Massive black hole binaries and where to find them with dual detector networks

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 (MBHBs). We consider two scenarios: a network composed of the Laser Interferometer Space Antenna (LISA) and an additional LISA-like heliocentric detector (e.g., Taiji), and a network composed of LISA with 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 Taiji or TianQin, we find lower uncertainties in the extrinsic parameters of both higher and lower mass MBHBs. Our most significant results are in sky location and luminosity distance. For sky location, we find several orders of magnitude improvements for high mass binaries and an order of magnitude improvement in low mass binaries. For luminosity distance, we find an order of magnitude improvement for high mass binaries and no improvement for low mass binaries.

Automated summary

A network of space-based gravitational wave detectors can greatly improve source localization and parameter estimation, especially for massive black hole binaries.