Gravitational Wave Memory of Gamma-Ray Burst Jets

TL;DR

This paper investigates the gravitational wave signals produced by gamma-ray burst jets during their acceleration phase, highlighting their detectability and the importance of gravitational wave observations for understanding jet structures.

Contribution

It demonstrates that the gravitational waveform from GRB jets has unique features and that upcoming detectors could observe these signals, providing new insights into jet physics.

Findings

Waveforms have step function-like jumps.

Detection is possible with DECIGO and BBO in the Local group.

Gravitational wave signals are anti-correlated with GRB light curves.

Abstract

Gamma-Ray Bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of the jet is larger than the inverse of the Lorentz factor of the jet, (ii) the gravitational waveform has many step function like jumps, and (iii) the practical DECIGO and BBO may detect such an event if the GRBs occur in Local group of galaxy. We found that the light curve of GRBs and the gravitational waveform are anti-correlated so that the detection of the gravitational wave is indispensable to determine the structure of GRB jets.