Core-Collapse Supernova Equations of State Based on Neutron Star Observations

Abstract

Many of the currently available equations of state for core-collapse supernova simulations give large neutron star radii and do not provide large enough neutron star masses, both of which are inconsistent with some recent neutron star observations. In addition, one of the critical uncertainties in the nucleon-nucleon interaction, the nuclear symmetry energy, is not fully explored by the currently available equations of state. In this article, we construct two new equations of state which match recent neutron star observations and provide more flexibility in studying the dependence on nuclear matter properties. The equations of state are also provided in tabular form, covering a wide range in density, temperature and asymmetry, suitable for astrophysical simulations. These new equations of state are implemented into our spherically symmetric core-collapse supernova model, which is based on general relativistic radiation hydrodynamics with three-flavor Boltzmann neutrino transport. The results are compared with commonly used equations of state in supernova simulations of 15 and 40 M ⊙ progenitors. We do not find any simple correlations between individual nuclear matter properties at saturation and the outcome of these simulations. However, the new equations of state lead to the most compact neutron stars among the relativistic mean-field models which we considered. The new models also obey the previously observed correlation between the time to black hole formation and the maximum mass of an s = 4 neutron star.

Crucial Physical Dependencies of the Core-Collapse Supernova Mechanism

“…In 2D, rotation and a third component of the velocity vector can be included in the hydrodynamics. We use the SFHo equation of state (EOS) by default (Steiner et al 2013), but in this paper do compare with results using the DD2 EOS (Banik et al 2014). 2 For these simulations, we follow twenty energy (ε ν ) groups for each of the ν e ,ν e , and "ν μ " species (again, the four species, ν μ ,ν μ , ν τ , andν τ lumped together.)…”

Quasi-Periodic Gravitational-Wave Emission due to the SASI Motion

“…We use three EoSs based on the relativistic-mean-field theory with different nuclear interaction treatments, which are DD2 and TM1 of [6] and SFHx of [7]. By considering, such as, their symmetry energy at nuclear saturation density and the radius of cold NS, SFHx is the softest EOS followed in order by DD2, and TM1 [8].…”

Nuclear phase transition and thermodynamic instabilities in dense nuclear matter

“…Here and in the following, we focus our investigation by considering the so-called GM3 [4] and the SFHo parameter sets [17,18]. The implementation of hyperon degrees of freedom comes from determination of the corresponding meson-hyperon coupling constants that have been fitted to hypernuclear properties.…”

“…3, we show the temperature as a function of the baryon density (in units of the saturation nuclear density), in absence (np) and in presence (npH) of hyperons in the SFHo model [17,22]. We limit our analysis in the first two phases: in the left panel, the first leptonic rich state (s = 1, Y L = 0.4) and, in the right panel, the maximum heating phase (s = 2, Y ν e = 0).…”