# Accuracy of Estimating Highly Eccentric Binary Black Hole Parameters with Gravitational-Wave Detections

## TL;DR

This paper assesses how well gravitational-wave detectors can measure parameters of highly eccentric binary black hole mergers, finding that eccentricity can significantly improve measurement accuracy depending on initial conditions.

## Contribution

It introduces a Fisher matrix-based method to evaluate parameter estimation accuracy for eccentric binaries, accounting for relativistic effects and orbital evolution.

## Key findings

- Eccentric sources can yield higher signal-to-noise ratios than circular ones.
- Parameter measurement accuracy improves with initial eccentricity and specific orbital parameters.
- Eccentric binaries can significantly enhance sky localization and chirp mass estimation.

## Abstract

Mergers of stellar-mass black holes on highly eccentric orbits are among the targets for ground-based gravitational-wave detectors, including LIGO, VIRGO, and KAGRA. These sources may commonly form through gravitational-wave emission in high velocity dispersion systems or through the secular Kozai-Lidov mechanism in triple systems. Gravitational waves carry information about the binaries' orbital parameters and source location. Using the Fisher matrix technique, we determine the measurement accuracy with which the LIGO-VIRGO-KAGRA network could measure the source parameters of eccentric binaries using a matched filtering search of the repeated burst and eccentric inspiral phases of the waveform. We account for general relativistic precession and the evolution of the orbital eccentricity and frequency during the inspiral. We find that the signal-to-noise ratio and the parameter measurement accuracy may be significantly higher for eccentric sources than for circular sources. This increase is sensitive to the initial pericenter distance, the initial eccentricity, and component masses. For instance, compared to a 30 Msun-30 Msun non-spinning circular binary, the chirp mass and sky localization accuracy can improve for an initially highly eccentric binary by a factor of ~129 (38) and ~2 (11) assuming an initial pericenter distance of 20 Mtot (10 Mtot).