Properties of Neutron stars with hyperon cores in parametrized hydrostatic conditions

Abstract

Models of neutron stars (NSs) with hyperon cores are constructed with an effective chiral model in mean-field approximation. The hyperon couplings are fixed by reproducing their experimentally determined binding energies. The impact of these couplings on population of different particles and the equation of state (EoS) are studied in this work. The global properties of NSs like gravitational mass, radius, baryonic mass and central density are calculated using parametrized Tolman–Oppenheimer–Volkoff equations (PTOVs) with special emphasis on two effects of pressure — one contributing to total mass density and the other to self-gravity of the star. We find that with PTOV solutions in static conditions, a softer EoS (including hyperons) can also lead to massive stellar configurations of NSs, which are in good agreement with the observed maximum mass bound of [Formula: see text] (PSR J0348-0432). Estimates of [Formula: see text] and [Formula: see text], obtained with the PTOV equations, are consistent with the recent findings of the same from the data analysis of gravitational waves (GW170817) observation.