Multimessenger signal from phase transition of neutron star to quark star

TL;DR

This paper explores the multimessenger signals, including neutrinos, gravitational waves, and electromagnetic observations, resulting from the phase transition of a neutron star into a quark star, highlighting potential observable signatures.

Contribution

It introduces a detailed model of the phase transition process and predicts multimessenger signals, including neutrino, gravitational wave, and electromagnetic signatures, from neutron star to quark star conversion.

Findings

Neutrino-antineutrino annihilation energy matches short gamma-ray burst observations.

Misalignment angle evolution affects pulsar radio intensity.

Gravitational wave signals include continuous and burst emissions.

Abstract

Aim: To study the multimessenger nature of the signal that can result from the phase transition of a neutron star to a quark star and their corresponding astrophysical observations. Methods: The phase transition process is initiated by the abrupt pressure and density changes at the star center, giving rise to a shock which deconfines matter followed by a weak front converting excess down to strange quarks to attain absolute stability. This process's effects are investigated by understanding how the energy escapes from the star in the form of neutrino-antineutrino annihilation. For such annihilation process, the corresponding energy deposition rate is calculated. Structural changes due to the energy loss have been investigated in the likes of misalignment angle evolution of the star and its astrophysical observation through gravitational waves. Results: The energy and time signature for the neutrino-antineutrino annihilation is compared with the observed isotropic energy for a short gamma-ray burst. The misalignment angle evolves to align the star's tilt axis, which can lead to the sudden increase or decrease of radio intensity from the pulsar. The corresponding gravitational wave emission, both continuous and burst, all lead towards multimessenger signals coming from the phase transition.