Black hole binary inspiral and trajectory dominance

TL;DR

This paper explores how the trajectories of inspiraling black holes influence the gravitational wave recoil, providing insights into the spin-dependent dynamics that cause the observed kicks during black hole mergers.

Contribution

It links the phenomenology of linear momentum waveforms to the underlying spin-dependent inspiral trajectories, enhancing understanding of black hole recoil mechanisms.

Findings

Partial cancellation of early and late kicks explained by waveform phenomenology

Spin influences the inspiral trajectories and resulting recoil

Trajectory analysis offers broader understanding of plunge dynamics

Abstract

Gravitational waves emitted during the inspiral, plunge and merger of a black hole binary carry linear momentum. This results in an astrophysically important recoil to the final merged black hole, a ``kick'' that can eject it from the nucleus of a galaxy. In a previous paper we showed that the puzzling partial cancellation of an early kick by a late antikick, and the dependence of the cancellation on black hole spin, can be understood from the phenomenology of the linear momentum waveforms. Here we connect that phenomenology to its underlying cause, the spin-dependence of the inspiral trajectories. This insight suggests that the details of plunge can be understood more broadly with a focus on inspiral trajectories.