Parameter estimation for inspiraling eccentric compact binaries including pericenter precession

TL;DR

This paper investigates how orbital eccentricity and pericenter precession in inspiraling supermassive black hole binaries affect gravitational wave parameter estimation, showing eccentricity improves localization and mass measurement accuracy.

Contribution

It provides a detailed analysis of parameter estimation improvements due to eccentricity and precession effects using Fisher matrix and Monte Carlo methods.

Findings

Eccentricity significantly enhances source localization accuracy.

Pericenter precession improves mass and eccentricity estimation by a factor of 3-10.

Higher-mass binaries benefit most from eccentricity in parameter estimation.

Abstract

Inspiraling supermassive black hole binary systems with high orbital eccentricity are important sources for space-based gravitational wave (GW) observatories like the Laser Interferometer Space Antenna (LISA). Eccentricity adds orbital harmonics to the Fourier transform of the GW signal and relativistic pericenter precession leads to a three-way splitting of each harmonic peak. We study the parameter estimation accuracy for such waveforms with different initial eccentricity using the Fisher matrix method and a Monte Carlo sampling of the initial binary orientation. The eccentricity improves the parameter estimation by breaking degeneracies between different parameters. In particular, we find that the source localization precision improves significantly for higher-mass binaries due to eccentricity. The typical sky position errors are $\sim1 $deg for a nonspinning, $10^7\,M_{\odot}$ equal-mass binary at redshift $z=1$, if the initial eccentricity 1 yr before merger is $e_0\sim 0.6$. Pericenter precession does not affect the source localization accuracy significantly, but it does further improve the mass and eccentricity estimation accuracy systematically by a factor of 3--10 for masses between $10^6$ and $10^7\,M_{\odot}$ for $e_0 \sim 0.3$.