Neutron star equation of state and GW170817

TL;DR

This paper investigates neutron star properties using various equations of state in light of GW170817 data, constraining the stiffness of EoS and estimating physical parameters like moments of inertia.

Contribution

It introduces a comprehensive analysis of neutron star EoS involving nucleons, hyperons, and quarks, applying consistent EoS to merger components and deriving observational constraints.

Findings

Soft to moderately stiff EoS are consistent with GW170817 data.

Stiffest hadron-quark EoS is ruled out by gravitational wave constraints.

A correlation between tidal deformabilities and masses is confirmed.

Abstract

Properties of neutron stars in GW170817 are investigated using different equations of state (EoS) involving nucleons, $\Lambda$ hyperons, quarks resulting in $2M_{\odot}$ neutron stars. This calculation is performed using the same EoS for merger components and for low spin prior case. It is found from the computations of tidal deformability parameters that soft to moderately stiff equations of state are allowed by the 50$\%$ and 90$\%$ credible regions obtained from the gravitational wave observation of binary neutron star merger GW170817, whereas the stiffest hadron-quark EoS which lies above the upper 90$\%$ limit, is ruled out. A correlation among the tidal deformabilities and masses is found to exist as already predicted. Furthermore moments of inertia and quadrupole moments of merger components of GW170817 are estimated.