The internal composition of proto-neutron stars under strong magnetic fields

TL;DR

This paper investigates how strong magnetic fields and rotation influence the structure and composition of proto-neutron stars using a relativistic model, revealing significant effects on neutrino trapping, strangeness, and temperature during evolution.

Contribution

It provides a self-consistent relativistic analysis of proto-neutron stars with magnetic fields, including effects of neutrino trapping and chemical evolution, which advances understanding of their internal composition.

Findings

Magnetic fields deform the star's structure.

Magnetic fields alter neutrino trapping and composition.

Temperature and strangeness content are significantly affected.

Abstract

In this work, we study the effects of magnetic fields and rotation on the structure and composition of proto-neutron stars (PNS's). A hadronic chiral SU(3) model is applied to cold neutron stars (NS) and proto-neutron stars with trapped neutrinos and at fixed entropy per baryon. We obtain general relativistic solutions for neutron and proto-neutron stars endowed with a poloidal magnetic field by solving Einstein-Maxwell field equations in a self-consistent way. As the neutrino chemical potential decreases in value over time, this alters the chemical equilibrium and the composition inside the star, leading to a change in the structure and in the particle population of these objects. We find that the magnetic field deforms the star and significantly alters the number of trapped neutrinos in the stellar interior, together with strangeness content and temperature in each evolution stage.