Kilonova Emissions from Neutron Star Merger Remnants: Implications for Nuclear Equation of State

TL;DR

This study uses advanced simulations and observations of neutron star mergers to constrain the nuclear equation of state, particularly the neutron star radius and maximum mass, through kilonova light curve analysis.

Contribution

It introduces a novel method linking kilonova observations to the nuclear EoS using detailed simulations and applies it to GW170817 data.

Findings

Neutron star radius constrained between 10.19 and 13.0 km.

Maximum neutron star mass constrained to be less than 3.06 solar masses.

Method connects electromagnetic signals to nuclear physics properties.

Abstract

Multi-messenger observation of binary neutron-star mergers can provide valuable information on the nuclear equation of state (EoS). Here, we investigate to which extent electromagnetic observations of the associated kilonovae allow us to place constraints on the EoS. For this, we use state-of-the-art three-dimensional general-relativistic magneto-hydrodynamics simulations and detailed nucleosynthesis modeling to connect properties of observed light curves to properties of the accretion disk, and hence, the EoS. Using our general approach, we use multi-messenger observations of GW170817/AT2017gfo to study the impact of various sources of uncertainty on inferences of the EoS. We constrain the radius of a $\rm{1.4 M_\odot}$ neutron star to lie within $\rm{10.19\leq R_{1.4}\leq 13.0}$~km and the maximum mass to be $\rm{M_{TOV}\leq 3.06 M_\odot}$.