Statified model of a neutron star

Abstract

Evolutionary calculations based on realistic equations of state indicate the stratified nature of the distribution of hadron matter in the interiors of neutron stars. In the proposed model, the stratified structure of a neutron star is treated as a rigid inert core surrounded by a dynamical layer. The physical basis for the model is the concept of the stellar matter of the peripheral envelope as an elastic Fermi continuum, the motions of which are described by the equations of nuclear elastodynamics, proposed in the macroscopic theory of collective processes in laboratory nuclear physics. It is shown that the vibrational dynamics of a neutron star is characterized by two branches of gravitational—elastic, spheroidal (s-mode) and torsional (t-mode) nonradial eigenvibrations. Estimates obtained for the periods of global, gravitational nonradial modes suggest that variations in the intensity of micropulses observed in the millisecond range of the spectra of C-pulsars may be ascribed to these vibrations. The proposed two-component model of a neutron star enables one to consider a glitch in a pulsar’s radio emission as a starquake due to the passage of the companion through periastron of the binary system.