Crystallization of the outer crust of a non-accreting neutron star

Understand

The interior of a neutron star (NS) is usually assumed to be made of cold catalyzed matter.

• However, the outer layers are unlikely to remain in full equilibrium during the formation of the star and its cooling, especially after crystallization.
• We study the cooling and equilibrium composition of the outer layers of a NS down to crystallization.
• Here the impurity parameter, usually a free parameter in cooling simulations, is calculated self-consistently using a microscopic model for which a unified equation of state has recently been determined.