The Effects of Interior Magnetic Fields on the Properties of Neutron Stars in the Relativistic Mean‐Field Theory

Abstract

We investigate the gross properties of the dense neutron star matter and the structure of the stars under the influence of strong magnetic fields, based on two nonlinear σ - ω models of nuclear matter, i.e., the BB and the ZM models, within the relativistic mean-field approximation. Contrary to the results obtained in the linear σ - ω model and the BB model, we find that the influence of the magnetic field on the effective nucleon mass m* is not significant in the ZM model; therefore, we predict that the neutrons in the interior of a neutron star might be superfluid according to the ZM model, if there is a strong magnetic field in the interior of the star. Moreover, the equations of state (EOSs) will become softer and softer with the increase of the strength of the magnetic field B. We show the effects of the interior magnetic fields on the gross properties of neutron stars, such as the critical masses, their corresponding radii, the moment of inertia, the crust masses, the crust moment of inertia, and the gravitational redshift in both nonlinear σ - ω models.