Revisiting GW150914 with a non-planar, eccentric waveform model

TL;DR

This paper revisits GW150914 using a novel waveform model that accounts for non-circular, non-planar binary black hole mergers, providing updated source parameters and analyzing various source scenarios including eccentricity and precession.

Contribution

It introduces the first inspiral-merger-ringdown waveform model that includes both eccentricity and precession effects for binary black hole analysis.

Findings

Signal is consistent with a quasi-circular, slowly spinning binary black hole merger.

Model validates previous results with improved parameter estimation.

First analysis using a model with both eccentricity and precession.

Abstract

The first direct detection of gravitational waves by the LIGO collaboration, GW150914, marked the start of a new exciting era in astronomy, enabling the study of the Universe through a new messenger. Since then, the field has grown rapidly, with the development of increasingly more sophisticated techniques to detect, analyze and interpret the signals. In this paper we revisit GW150914, presenting updated estimates of its source parameters using a waveform model developed within the EOB formalism, able to describe gravitational-wave emission from generic non-circular, non-planar binaries. We provide a comprehensive analysis of the signal and its properties, considering and contrasting various scenarios for the source: from the simplest, aligned-spin quasi-circular binary black hole merger, to more complex scenarios, including precession, eccentricity or both. Unsurprisingly, we find that the signal is consistent with a quasi-circular ($e < 0.08$ at $15$ Hz), slowly spinning $(\chi_{\rm eff} = -0.03^{+0.12}_{-0.13})$ binary black hole merger, a-posteriori validating a considerable body of works. This is the first analysis performed with an inspiral-merger-ringdown model containing both eccentricity and precession.