Quark-hadron phase transition in a neutron star under strong magnetic fields

TL;DR

This paper investigates how strong magnetic fields influence the internal structure and phase transitions of neutron stars, showing that magnetic fields can prevent quark phase formation and alter star properties.

Contribution

It introduces models of density-dependent magnetic fields and analyzes their impact on neutron star composition and maximum mass, highlighting the magnetic field's role in stellar evolution.

Findings

Magnetic fields prevent the appearance of quark phases in neutron stars.

Stronger magnetic fields increase the maximum mass and radius of neutron stars.

The magnetic field parametrization significantly affects star properties.

Abstract

We study the effect of a strong magnetic field on the properties of neutron stars with a quark-hadron phase transition. It is shown that the magnetic field prevents the appearance of a quark phase, enhances the leptonic fraction, decreases the baryonic density extension of the mixed phase and stiffens the total equation of state, including both the stellar matter and the magnetic field contributions. Two parametrisations of a density dependent static magnetic field, increasing, respectively, fast and slowly with the density and reaching $2-4\times 10^{18}$G in the center of the star, are considered. The compact stars with strong magnetic fields have maximum mass configurations with larger masses and radius and smaller quark fractions. The parametrisation of the magnetic field with density has a strong influence on the star properties.