X-Ray Flares of Gamma-Ray Bursts: Quakes of Solid Quark Stars?

TL;DR

This paper introduces a star-quake model for X-ray flares in gamma-ray bursts, suggesting solid quark stars as central engines and proposing elastic and gravitational energy as power sources.

Contribution

It presents a novel star-quake model involving solid quark stars to explain X-ray flares in both long and short GRBs, highlighting a new energy source.

Findings

Solid quark stars can form 10^3 to 10^6 seconds after birth.

Elastic and gravitational energy can power GRB X-ray flares.

Two types of central engines for GRBs are proposed.

Abstract

We propose a star-quake model to understand X-ray flares of both long and short Gamma-ray bursts (GRBs) in a solid quark star regime. Two kinds of central engines for GRBs are available if pulsar-like stars are actually (solid) quark stars, i.e., the SNE-type GRBs and the SGR-type GRBs. It is found that a quark star could be solidified about 10^3 to 10^6 s later after its birth if the critical temperature of phase transition is a few MeV, and then a new source of free energy (i.e., elastic and gravitational ones, rather than rotational or magnetic energy) could be possible to power GRB X-ray flares.