LISA parameter estimation of supermassive black holes

TL;DR

This paper evaluates how including higher harmonics in gravitational waveforms improves parameter estimation of supermassive black holes by LISA, especially for source localization and electromagnetic counterpart identification.

Contribution

It demonstrates that higher harmonics significantly enhance parameter estimation accuracy and source localization compared to the restricted post-Newtonian approximation.

Findings

Higher harmonics improve parameter estimation accuracy.

Enhanced source localization and electromagnetic counterpart identification.

Mitigation of laser link loss impact during the mission.

Abstract

We study parameter estimation of supermassive black holes in the range $10^5-10^8\Ms$ by LISA using the inspiral full post-Newtonian gravitational waveforms, and we compare the results with those arising from the commonly used restricted post-Newtonian approximation. The analysis shows that for observations of the last year before merger, the inclusion of the higher harmonics clearly improves the parameter estimation. We pay special attention to the source location errors and we study the improvement on the percentage of sources for which we could potentially identify electromagnetic counterparts. We also show how the additional harmonics can help to mitigate the impact of losing laser links during the mission.