A more effective coordinate system for parameter estimation of precessing compact binaries from gravitational waves

TL;DR

This paper introduces a new coordinate system for analyzing gravitational wave data from merging compact binaries, improving the efficiency and interpretability of parameter estimation in ground-based detectors.

Contribution

It proposes a physically motivated coordinate system based on binary spins and a specific reference time, enhancing parameter estimation performance for gravitational wave signals.

Findings

Improved parameter estimation efficiency for BNS, NS-BH, and BBH signals.

Significant reduction in computational time for MCMC analysis.

Enhanced interpretability of binary system parameters.

Abstract

Ground-based gravitational wave detectors are sensitive to a narrow range of frequencies, effectively taking a snapshot of merging compact-object binary dynamics just before merger. We demonstrate that by adopting analysis parameters that naturally characterize this 'picture', the physical parameters of the system can be extracted more efficiently from the gravitational wave data, and interpreted more easily. We assess the performance of MCMC parameter estimation in this physically intuitive coordinate system, defined by (a) a frame anchored on the binary's spins and orbital angular momentum and (b) a time at which the detectors are most sensitive to the binary's gravitational wave emission. Using anticipated noise curves for the advanced-generation LIGO and Virgo gravitational wave detectors, we find that this careful choice of reference frame and reference time significantly improves parameter estimation efficiency for BNS, NS-BH, and BBH signals.