A New Equation of State for Astrophysical Simulations

TL;DR

This paper introduces a comprehensive, thermodynamically consistent equation of state for nuclear matter, covering wide astrophysical conditions, and provides an interpolated, ready-to-use table for simulations of supernovae and neutron star mergers.

Contribution

It combines extensive precomputed data into a single, fine-grid EOS table with improved interpolation, ensuring thermodynamic consistency for astrophysical simulations.

Findings

The EOS table is thermodynamically consistent.

The new EOS covers a wide range of temperatures, densities, and proton fractions.

The table is available for download and comparison with existing models.

Abstract

We generate a new complete equation of state (EOS) of nuclear matter for a wide range of temperatures, densities, and proton fractions ready for use in astrophysical simulations of supernovae and neutron star mergers. Our previous two papers tabulated the EOS at over 180,000 grid points in the temperature range $T$ = 0 to 80 MeV, the density range $n_B$ = 10$^{-8}$ to 1.6 fm$^{-3}$, and the proton fraction range $Y_P$ = 0 to 0.56. In this paper we combine these data points using a suitable interpolation scheme to generate a single equation of state table on a finer grid. This table is thermodynamically consistent and conserves entropy during adiabatic compression tests. We present various thermodynamic quantities and the composition of matter in the new EOS, along with several comparisons with existing EOS tables. Our equation of state table is available for download.