# Neutron star cooling and GW170817 constraint within quark-meson coupling models

## TL;DR

This study evaluates five quark-meson coupling models to analyze neutron star cooling and GW170817 constraints, finding correlations between the symmetry energy slope and cooling rates, but no single model fits all observations.

## Contribution

It compares different QMC models with various confinement potentials and assesses their ability to satisfy GW170817 constraints and neutron star cooling data.

## Key findings

- No model simultaneously satisfies GW170817 and cooling observations.
- Cooling rate correlates with the slope of the symmetry energy.
- Pasta phase has negligible impact on results.

## Abstract

In the present work we used five different versions of the quark-meson coupling (QMC) model to compute astrophysical quantities related to the GW170817 event and to neutron star cooling process. Two of the models are based on the original bag potential structure and three versions consider a harmonic oscillator potential to confine the quarks. The bag-like models also incorporate the pasta phase used to describe the inner crust of neutron stars. We show that the pasta phase always play a minor or negligible role in all studies. Moreover, while no clear correlation between the models that satisfy the GW170817 constraints and the slope of the symmetry energy is found, a clear correlation is observed between the slope and the fact that the cooling is fast or slow, i.e., fast (slow) cooling is related to higher (lower) values of the slope. We did not find one unique model that can describe, at the same time, GW170817 constraints and give a perfect description of the possible cooling processes.