The property difference between the neutron star PSR J0348+0432 and its proto neutron star

TL;DR

This study compares the properties of the neutron star PSR J0348+0432 and its proto neutron star using relativistic mean field theory, highlighting differences in density and hyperon production influenced by temperature.

Contribution

It provides a detailed analysis of the property differences between a specific neutron star and its proto form considering neutrino trapping and hyperon production.

Findings

Proto neutron star has lower central baryon density than neutron star.

Hyperons appear in proto neutron star but not in mature neutron star.

Higher temperature favors hyperon production in proto neutron stars.

Abstract

The property difference between the neutron star PSR J0348+0432 and its proto neutron star is studied in the framework of the relativistic mean field theory considering neutrino trapping. We see that the central baryon number density of the proto neutron star PSR J0348+0432 is in the range $\rho_{c, PNS}=0.539\sim0.698$ fm$^{-3}$, which is smaller than that of the neutron star PSR J0348+0432 $\rho_{c, NS}=0.634\sim0.859$ fm$^{-3}$. Inside the neutron star PSR J0348+0432, only the neutrons, protons, $\Lambda$ and $\Xi^{-}$ produce, whereas the hyperons $\Sigma^{-}, \Sigma^{0}, \Sigma^{+}$ and $\Xi^{0}$ all do not appear. But in the proto neutron star PSR J0348+0432, hyperons $\Sigma^{-}$, $\Sigma^{0}$, $\Sigma^{+}$ and $\Xi^{0}$ all will produce, though their relative particle number density are still very small, no more than 2\%. This shows that higher temperature will be advantageous to the hyperon production.