Observational constraint from the heaviest pulsar PSR J0952-0607 on the equation of state of dense matter in relativistic mean field model

Abstract

In the present work, we constrain the equation of state of dense matter in the context of heaviest observed neutron-star mass ${M}_{\mathrm{max}}=(2.35\ifmmode\pm\else\textpm\fi{}0.17){M}_{\ensuremath{\bigodot}}$ for the black widow pulsar PSR J0952-0607. We propose three interactions HPU1, HPU2 and HPU3 (named after Himachal Pradesh University) for the relativistic mean-field model, which include different combinations of nonlinear, self-couplings, and cross couplings among isoscalar-scalar $\ensuremath{\sigma}$, and isoscalar-vector $\ensuremath{\omega}$ and isovector-vector $\ensuremath{\rho}$ meson fields up to the quartic order. These interactions are in harmony with the finite nuclei and bulk nuclear matter properties. The equations of state computed by using newly generated interactions for the $\ensuremath{\beta}$-equilibrated nucleonic matter satisfy the heaviest observed neutron-star mass ${M}_{\mathrm{max}}=(2.35\ifmmode\pm\else\textpm\fi{}0.17){M}_{\ensuremath{\bigodot}}$ for the black widow pulsar PSR J0952-0607. The results for the radius ${R}_{1.4}$ and dimensionless tidal deformability ${\mathrm{\ensuremath{\Lambda}}}_{1.4}$ corresponding to the canonical mass are also presented and agree well with the GW170817 event and astrophysical observations. The radius of $2.08{M}_{\ensuremath{\bigodot}}$ neutron-star mass is predicted to be in the range ${R}_{2.08}=12.98$--13.09 km which also satisfy the NICER observations by Miller et al. [Astrophys. J. Lett. 918, L28 (2021)] and Riley et al. [Astrophys. J. Lett. 918, L27 (2021)]. A covariance analysis is also performed to assess the theoretical uncertainties of model parameters and to determine their correlations with nuclear matter observables.