Dynamical evolution of quasi-circular binary black hole data

TL;DR

This paper investigates the nonlinear evolution of binary black hole systems starting from quasi-circular initial data, revealing rapid coalescence and insights into the final black hole's properties, with implications for gravitational wave signals.

Contribution

It provides the first detailed numerical analysis of the dynamical evolution from quasi-circular initial conditions, including the final black hole's physical parameters and energy radiated.

Findings

Black holes coalesce in less than half an orbit from initial data.

Final black hole properties can be accurately measured with sufficient resolution.

Less than 3% of total energy is radiated during merger.

Abstract

We study the fully nonlinear dynamical evolution of binary black hole data, whose orbital parameters are specified via the effective potential method for determining quasi-circular orbits. The cases studied range from the Cook-Baumgarte innermost stable circular orbit (ISCO) to significantly beyond that separation. In all cases we find the black holes to coalesce (as determined by the appearance of a common apparent horizon) in less than half an orbital period. The results of the numerical simulations indicate that the initial holes are not actually in quasi-circular orbits, but that they are in fact nearly plunging together. The dynamics of the final horizon are studied to determine physical parameters of the final black hole, such as its spin, mass, and oscillation frequency, revealing information about the inspiral process. We show that considerable resolution is required to extract accurate physical information from the final black hole formed in the merger process, and that the quasi-normal modes of the final hole are strongly excited in the merger process. For the ISCO case, by comparing physical measurements of the final black hole formed to the initial data, we estimate that less than 3% of the total energy is radiated in the merger process.