Phase shift of gravitational waves induced by aberration

TL;DR

This paper investigates how the aberration effect, similar to that in light, influences the phase of gravitational waves from moving sources, potentially improving detection methods for astrophysical systems with acceleration or recoil.

Contribution

It introduces the concept of aberrational phase shift in gravitational waveforms and demonstrates its significance in modeling accelerating or recoiling sources.

Findings

Aberrational phase shift can be detectable in recoiling binary black holes.

Including aberration improves waveform modeling for moving sources.

Aberration effects could enhance gravitational wave source detectability.

Abstract

The velocity of a gravitational wave (GW) source provides crucial information about its formation and evolution processes. Previous studies considered the Doppler effect on the phase of GWs as a potential signature of a time-dependent velocity of the source. However, the Doppler shift only accounts for the time component of the wave vector, and in principle motion also affects the spatial components. The latter effect, known as ``aberration'' for light, is analyzed in this paper for GWs and applied to the waveform modeling of an accelerating source. We show that the additional aberrational phase shift could be detectable in two astrophysical scenarios, namely, a recoiling binary black hole (BBH) due to GW radiation and a BBH in a triple system. Our results suggest that adding the aberrational phase shift in the waveform templates could significantly enhance the detectability of moving sources.