Degeneracies in Sky Localisation Determination from a Spinning Coalescing Binary through Gravitational Wave Observations: a Markov-Chain Monte-Carlo Analysis for two Detectors

TL;DR

This paper uses Markov-chain Monte-Carlo simulations to analyze how black-hole spin affects sky localization of gravitational-wave signals from binary inspirals, highlighting degeneracies with data from only two detectors.

Contribution

It introduces a detailed MCMC-based approach to assess sky localization degeneracies caused by black-hole spin in gravitational-wave observations.

Findings

Black-hole spin significantly impacts sky localization accuracy.

Degeneracies are more pronounced with only two detectors.

Higher post-Newtonian order waveforms influence parameter estimation.

Abstract

Gravitational-wave signals from inspirals of binary compact objects (black holes and neutron stars) are primary targets of the ongoing searches by ground-based gravitational-wave interferometers (LIGO, Virgo, and GEO-600). We present parameter-estimation simulations for inspirals of black-hole--neutron-star binaries using Markov-chain Monte-Carlo methods. As a specific example of the power of these methods, we consider source localisation in the sky and analyse the degeneracy in it when data from only two detectors are used. We focus on the effect that the black-hole spin has on the localisation estimation. We also report on a comparative Markov-chain Monte-Carlo analysis with two different waveform families, at 1.5 and 3.5 post-Newtonian order.