Gravitational wave bursts from long gamma-ray bursts

TL;DR

This paper suggests that long gamma-ray bursts originate from core-collapse black holes, which produce gravitational wave bursts correlated with electromagnetic signals, enabling potential detection and estimation of black hole spin.

Contribution

It introduces a model linking gamma-ray burst properties to gravitational wave emissions from black hole formation, proposing a method to estimate gravitational wave signals from observed gamma-ray bursts.

Findings

Gravitational wave bursts are expected from long gamma-ray bursts due to core-collapse.

The strength of these gravitational waves depends on the black hole's spin.

Detectability of these signals varies with current and future gravitational wave detectors.

Abstract

One of the most luminous explosions detected, gamma-ray bursts, especially the so-called long-duration bursts, most probably consist of an intrinsic core-collapse to a black hole inside a super massive star. We point out that this collapse alone will give a generic gravitational wave burst. It has been shown that the strength of this burst depends on the dimensionless spin parameter of the collapsing object. Under descent assumptions the gamma-ray burst's central engine powers the explosion electromagnetically due to the rotation of the newly formed black hole. We argue that the peak luminosity and the isotropic energy of the gamma-ray burst can be associated with the spin of the black hole, due to this mechanism. Since, both gravitational and electromagnetic emission depend on the spin, they can be correlated and thus give a straight estimate for the gravitational wave burst, when we have in hand a gamma-ray burst with known distance. We discuss detectability limits for present and future detectors.