LISA observations of supermassive black holes: parameter estimation using full post-Newtonian inspiral waveforms

TL;DR

This study evaluates how using full post-Newtonian waveforms enhances parameter estimation for supermassive black hole binaries in LISA observations, especially for high-mass systems, compared to restricted approximations.

Contribution

It demonstrates that full post-Newtonian waveforms significantly improve parameter estimation accuracy and extend the astrophysical reach of LISA for supermassive black hole binaries.

Findings

Improved angular resolution and distance measurement for high-mass systems.

Enhanced mass determination accuracy.

Extended observational reach to higher mass black hole binaries.

Abstract

We study parameter estimation of supermassive black hole binary systems in the final stage of inspiral using the full post-Newtonian gravitational waveforms. We restrict our analysis to systems in circular orbit with negligible spins, in the mass range $10^8\Ms-10^5\Ms$, and compare the results with those arising from the commonly used restricted post-Newtonian approximation. The conclusions of this work are particularly important with regard to the astrophysical reach of future LISA measurements. Our analysis clearly shows that modeling the inspiral with the full post-Newtonian waveform, not only extends the reach to higher mass systems, but also improves in general the parameter estimation. In particular, there are remarkable improvements in angular resolution and distance measurement for systems with a total mass higher than $5\times10^6\Ms$, as well as a large improvement in the mass determination.