# Rotating NSs/QSs and recent astrophysical observations

## TL;DR

This paper investigates rotating neutron stars, quark stars, and hybrid stars using updated equations of state, compares theoretical models with astrophysical observations, and explores implications for gamma-ray bursts and quark deconfinement.

## Contribution

It provides a comprehensive analysis of rotating compact stars with recent EoSs, compares models with glitch observations, and links star types to gamma-ray burst phenomena and quark matter formation.

## Key findings

- Glitch crisis persists in Vela-like pulsars.
- Quark stars have larger moments of inertia than neutron stars.
- Post-merger products of NS-NS mergers may be supramassive quark stars.

## Abstract

Both fast and slow configurations of rotating neutron stars (NSs) are studied with the recently-constructed unified NS EoSs. The calculations for pure quark stars (QSs) and hybrid stars (HSs) are also done, using several updated quark matter EoSs and Gibbs construction for obtaining hadron-quark mixed phase. All three types of EoSs fulfill the recent 2-solar-mass constrain. By confronting the glitch observations with the theoretical calculations for the crustal moment of inertia (MoI), we find that the glitch crisis is still present in Vela-like pulsars. An upcoming accurate MoI measurement (eg., a possible 10\% accuracy for pulsar PSR J0737-3039A) could distinguish QSs from NSs, since the MoIs of QSs are generally $> \sim 1.5 $ times larger than NSs and HSs, no matter the compactness and the mass of the stars. Using tabulated EoSs, we compute stationary and equilibrium sequences of rapidly rotating, relativistic stars in general relativity from the well-tested $rns$ code, assuming the matter comprising the star to be a perfect fluid. All three observed properties of the short gamma-ray bursts (SGRBs) internal plateaus sample are simulated using the rotating configurations of NSs/QSs as basic input. We finally argue that for some characteristic SGRBs, the post-merger products of NS-NS mergers are probably supramassive QSs rather than NSs, and NS-NS mergers are a plausible location for quark deconfinement and the formation of QSs.