Inner crust of neutron stars with mass-fitted Skyrme functionals

Abstract

The equation of state and composition of the inner crust of neutron stars at zero temperature are calculated, using the $T$ $=$ 0 version of the temperature-dependent extended Thomas-Fermi plus Strutinsky integral method, for each of a family of three functionals based on Skyrme-type forces BSk19, BSk20, and BSk21, which are characterized by different degrees of symmetry-energy stiffness, and also for the SLy4 functional. We also solve the Tolman-Oppenheimer-Volkoff equations to calculate the distribution of mass within the inner crust. Qualitatively similar results are found for all four functionals, and in particular the number of protons per Wigner-Seitz cell is in all cases equal to 40 throughout the inner crust.