Radiation from low-momentum zoom-whirl orbits

TL;DR

This paper investigates gravitational radiation from low-momentum zoom-whirl black hole binaries, revealing a maximum energy emission near one orbit, with energy radiated exceeding quasi-circular cases by 15%, and exploring eccentricity effects.

Contribution

It provides new insights into the radiation characteristics of low-momentum black hole binaries, highlighting the maximum energy emission and eccentricity dependence in full general relativity.

Findings

Maximum radiated energy occurs near one orbit

Energy radiated exceeds quasi-circular case by 15%

Eccentricity shows multiple local maxima and minima

Abstract

We study zoom-whirl behaviour of equal mass, non-spinning black hole binaries in full general relativity. The magnitude of the linear momentum of the initial data is fixed to that of a quasi-circular orbit, and its direction is varied. We find a global maximum in radiated energy for a configuration which completes roughly one orbit. The radiated energy in this case exceeds the value of a quasi-circular binary with the same momentum by 15%. The direction parameter only requires minor tuning for the localization of the maximum. There is non-trivial dependence of the energy radiated on eccentricity (several local maxima and minima). Correlations with orbital dynamics shortly before merger are discussed. While being strongly gauge dependent, these findings are intuitive from a physical point of view and support basic ideas about the efficiency of gravitational radiation from a binary system.