The precursor of GRB211211A: a tide-induced giant quake?

TL;DR

This paper investigates whether a tide-induced starquake in a solid strange star could explain the precursor emission observed before the merger event GRB211211A, suggesting a black hole-strangeon star scenario.

Contribution

It introduces a model of tide-induced starquakes in solid strange stars to explain precursor emissions in binary mergers, providing insights into the nature of GRB211211A.

Findings

Starquake energy may be insufficient unless the entire star shatters.

The model favors a black hole-strangeon star merger scenario.

Precursor timescale and oscillation frequency are consistent with observations.

Abstract

The equilibrium configuration of a solid strange star in the final inspiral phase with another compact object is generally discussed, and the starquake-related issue is revisited, for a special purpose to understand the precursor emission of binary compact star merger events (e.g., that of GRB211211A). As the binary system inspirals inward due to gravitational wave radiation, the ellipticity of the solid strangeon star increases due to the growing tidal field of its compact companion. Elastic energy is hence accumulated during the inspiral stage which might trigger a starquake before the merger when exceeds a critical value. The energy released during such starquakes is calculated and compared to the precursor observation of GRB211211A. The result shows that the energy might be insufficient for binary strangeon-star case unless the entire solid strangeon star shatters, and hence favors a black hole-strangeon star scenario for GRB211211A. The timescale of the precursor as well as the frequency of the observed quasi-periodic-oscillation have also been discussed in the starquake model.