Eur. Phys. J. A (2021) 57: 263
https://doi.org/10.1140/epja/s10050-021-00572-y

Regular Article - Theoretical Physics

Crust-core transition of a neutron star: effect of the temperature under strong magnetic fields

¹ Department of Physics, CFisUC, University of Coimbra, 3004-516, Coimbra, Portugal
² University of Carthage, BP 77, Avenue de la République, 1054, Amilcar, Tunisia

^b rabhi@uc.pt

Received: 4 June 2021
Accepted: 13 August 2021
Published online: 3 September 2021

Abstract

The effect of temperature on the crust-core transition of a magnetar is studied. The thermodynamical spinodals are used to calculate the transition region within a relativistic mean-field approach for the equation of state. Magnetic fields with intensities G and G are considered. It is shown that the effect on the extension of the crust-core transition is washed away for temperatures above K for magnetic field intensities G but may still persist if a magnetic field as high as G is considered. For temperatures below that value, the effect of the magnetic field on crust-core transition is noticeable and grows as the temperature decreases and, in particular, it is interesting to identify the existence of disconnected non-homogenous matter above the crust core transition density. Models with different symmetry energy slopes at saturation show quite different behaviors. In particular, a model with a large slope, as suggested by the recent results of PREX-2, predicts the existence of up to four disconnected regions of non-homogeneous matter above the zero magnetic field crust-core transition density.