| Neutron stars are formed by the residue of the supernova explosion, this process takes place at the end of the evolution of massive stars due to gravitational collapse effect. The density, temperature and magnetic field of a neutron star is dozens of times or even one hundred times as dense as that in the earth. The researches on the neutron stars especially proto-neutron stars which form after seconds of supernova explosions have very important effect to know the structure of material level. Especially, the discovery of massive neutron stars gives strong impetus on the astrophysics and particle physics. This article is based on the discussion of massive proto-neutron star and gives some important properties of massive proto-neutron star. The concrete work as followings.First, we calculate and analyze the properties of proto-neutron star of PSR J0348+0432. We select the reasonable parameter sets (nuclear coupling parameters, hyperon coupling parameters) under relativistic mean field theory to discuss the properties of massive neutron star PSR J0348+0432. We use these coupling parameter sets to extrapolate the massive proto-neutron star PSR J0348+0432 and then discuss the particle distribution, temperature distribution, the equation of state, mass-radius relation. It finds that there are more hyperons inside the proto-neutron stars. The existence of hyperons will reduce the internal temperature of proto-neutron star, and soften the equation of state, reduce the mass of the proto-neutron star.Second, we discuss the influence of gravitational correction on massive proto-neutron star through introducing the light vector U boson, and then revises the equation of state. The influence of U boson will give different results on pressure and energy density. The influence on the pressure are more obvious at low density than high density, while the influence on energy density are more obvious at high density than low density. U boson plays a significant role in increasing the mass and radius of proto-neutron star. The U boson will increase the moment of inertia and decrease the gravitational red-shift.Third, we discuss the influence of entropy on massive proto-neutron star. The entropy per baryon is selected from 0 to 3 during the evolution of the neutron star and discuss the influence on the massive neutron star PSR J1614-2230 and PSR J0348+0432. The entropy per baryon will stiffen the EOS (the equation of state) and the higher entropy per baryon is the stiffener the EOS is. The influence of entropy per baryon will give different results on pressure and energy density. The entropy per baryon will increase the maximum mass and radius of proto-neutron star. The entropy per baryon will increase the moment of inertia of massive proto-neutron star, contrarily decrease the effect of gravitational red-shift. The temperature will increase with the entropy per baryon increases.These results have significant reference value on neutron star theoretical research. |
PDF Full Text Request