Astrophysical constraints on a parametric equation of state for neutron-rich nucleonic matter

Abstract

Extracting the equation of state (EOS) and symmetry energy of dense neutron-rich matter from astrophysical observations is a long-standing goal of nuclear astrophysics. To facilitate the realization of this goal, the feasibility of using an explicitly isospin-dependent parametric EOS for neutron star matter was investigated recently in [1–3]. In this contribution, in addition to outlining the model framework and summarizing the most important findings from [1–3], we report a few new results regarding constraining parameters characterizing the high-density behavior of nuclear symmetry energy. In particular, the constraints on the pressure of neutron star matter extracted from combining the X-ray observations of the neutron star radius, the minimum–maximum mass $$M=2.01$$ $$\hbox {M}_\odot $$ , and causality condition agree very well with those extracted from analyzing the tidal deformability data by the LIGO + Virgo Collaborations. The limitations of using the radius and/or tidal deformability of neutron stars to constrain the high-density nuclear symmetry energy are discussed.