On the moment of inertia of PSR J0737-3039 A from LIGO/Virgo and NICER

Abstract

We extend our previous study (Li et al. 2021) on neutron stars with a quark core to predict the moment of inertia of pulsar A in the double pulsar binary J0737-3039, assuming there is a phase transition in the pulsar inner core from the soft QMF or the stiff DD2 hadronic equation of state (EOS) to a high-density phase of quark matter modelled by the generic "constant-sound-speed" (CSS) parameterization. We perform a Bayesian analysis of the moment of inertia by incorporating observational data for the tidal deformability of the GW170817 and GW190425 binary neutron star mergers, as detected by LIGO/Virgo, and the mass and radius of PSR J0030+0451 and MSP J0740+6620, as detected by the Neutron Star Interior Composition Explorer. We find that the most probable values of the moment of inertia of PSR J0737-3039 A are 1.27 +0.18 −0.14 × 10 45 g cm 2 for QMF+CSS and similarly 1.29 +0.26 −0.15 × 10 45 g cm 2 for DD2+CSS at 90% credible interval. We also demonstrate how a moment of inertia measurement would improve our knowledge of the EOS and the mass-radius relation for hybrid stars and discuss whether a quark deconfinement phase transition is supported by the available data and forthcoming data that could be consistent with this hypothesis.

Neutron stars in massive scalar-Gauss-Bonnet gravity: Spherical structure and time-independent perturbations

“…[44][45][46] when adequate observational data, for example, from the NS Interior Composition Explorer (NICER) mission, are collected and analyzed to be compared with the theoretical predictions. The x-ray pulsar observations are also expected to measure the moment of inertia for NSs [47,48], providing another avenue to constrain the theory when compared to the numerical results for the moment of inertia calculated here. The tidal deformability, extracted from GW observations of NS mergers like GW170817 [49], provides a third way to test the theory, and certain values for the parameters of the theory have been excluded by a comparison between the measurement from GW170817 and the numerical results calculated here.…”

Interacting $ud$ and $uds$ quark matter at finite densities and quark stars

“…In this sense, more advanced detection techniques in the future, rendering more precise measurements for masses and radii of compact stars, hold promise for constraining their composition (see recent discussions in e.g., Refs. [72][73][74].…”

Ensembles of unified crust and core equations of state in a nuclear-multimessenger astrophysics environment

“…Large sets of Skyrme [61,62], Gogny [63,64] and RMF models [65,66] have been used to construct sets of neutron star EOSs, although they do not systematically explore the space of symmetry energy parameterizations, and they are usually extended to the highest densities, implicitly assuming a nucleonic star with no phase transitions. Specific parameterizations of the Skyrme EDF have been used in conjunction with polytropic and speedof-sound parameterizations of the high density EOS [67,61,68,69]. Only a small number of studies have generated large ensembles of EDF models of the EOS, and additionally decoupled the high density EOS from the EDF through the use of polytropic extensions starting at 1.5-2n 0 [66].…”