Characterizing the effect of eccentricity on the dynamics of binary black hole mergers in numerical relativity

TL;DR

This study systematically examines how initial eccentricity influences the dynamics of binary black hole mergers across various configurations, revealing a universal oscillation pattern in key merger properties for non-spinning cases.

Contribution

It provides the first detailed analysis of the impact of initial eccentricity on multiple dynamic quantities in binary black hole mergers, using extensive numerical relativity simulations.

Findings

Discovery of a universal oscillation in dynamic quantities with eccentricity for non-spinning BBH.

Oscillation observed at specific separations and mass ratios, indicating eccentricity's significant role.

The oscillation phenomenon is absent in some mass ratios, highlighting the importance of initial conditions.

Abstract

Many articles have partially studied the configuration of eccentric orbital binary black hole (BBH) mergers. However, there is a scarcity of systematic and comprehensive research on the effect of eccentricity on BBH dynamics. Thanks to the rich and numerous numerical relativistic simulations of eccentric orbital BBH mergers from RIT catalog, this paper aims to investigate the impact of initial eccentricity $e_0$ on various dynamic quantities such as merger time $T_{\text{merger}}$, peak luminosity $L_{\text{peak}}$ of gravitational waves, recoil velocity $V_f$, mass $M_f$, and spin $\alpha_f$ of merger remnants. We cover configurations of no spin, spin alignment, and spin precession, as well as a broad parameter space of mass ratio ranging from 1/32 to 1 and initial eccentricity from 0 to 1. For non-spinning BBH with an initial coordinate separation of $11.3M$ ($M$ is the total mass of BBH), we make the first discovery of a ubiquitous oscillation in the relationship between dynamic quantities $L_{\text{peak}}$, $V_f$, $M_f$, $\alpha_f$, and initial eccentricity $e_0$. Additionally, at $24.6M$, we observe the same oscillation phenomenon in the case of mass ratio $q=1$, but do not see it in other mass ratios, suggesting that this oscillation will be evident in numerical simulations with sufficiently dense initial eccentricity. abbreviated