Realistic binary neutron star initial data with Elliptica

TL;DR

This paper presents Elliptica, a pseudo-spectral code capable of generating realistic initial data for binary neutron star systems, including tabulated equations of state and neutron star spins in any direction.

Contribution

The work extends Elliptica to incorporate tabulated equations of state and arbitrary neutron star spins, enhancing the realism of initial data for binary neutron star simulations.

Findings

Supports tabulated equations of state for neutron stars.

Allows neutron star spins near the mass shedding limit.

Enables arbitrary spin orientations in initial data.

Abstract

This work introduces the Elliptica pseudo-spectral code for generating initial data of binary neutron star systems. Building upon the recent Elliptica code update, we can now construct initial data using not only piecewise polytropic equations of state, but also tabulated equations of state for these binary systems. Furthermore, the code allows us to endow neutron stars within the binary system with spins. These spins can have a magnitude close to the mass shedding limit and can point in any direction.