Neutron star radii, deformabilities, and moments of inertia from experimental and ab initio theory constraints on the 208Pb neutron skin thickness

TL;DR

This study combines experimental, theoretical, and observational data to refine predictions of neutron star properties, such as radii, deformabilities, and moments of inertia, based on constraints from the 208Pb neutron skin thickness.

Contribution

It introduces a Bayesian framework integrating recent neutron skin measurements and ab initio theory to improve neutron star property estimates.

Findings

Neutron star radius for 1.4 solar masses: 12.36 km

Tidal deformability for 1.4 solar masses: 440

Moment of inertia for PSR J0737-3039A: 1.425 x 10^{45} g·cm²

Abstract

Recent experimental and ab initio theory investigations of the 208Pb neutron skin thickness are sufficiently precise to inform the neutron star equation of state. In particular, the strong correlation between the 208Pb neutron skin thickness and the pressure of neutron matter at normal nuclear densities leads to modified predictions for the radii, tidal deformabilities, and moments of inertia of typical 1.4 solar-mass neutron stars. In the present work, we study the relative impact of these recent analyses of the 208Pb neutron skin thickness on bulk properties of neutron stars within a Bayesian statistical analysis. Two models for the equation of state prior are employed in order to study the role of the highly uncertain high-density equation of state. From our combined Bayesian analysis of nuclear theory, nuclear experiment, and observational constraints on the dense matter equation of state, we find at the 90% credibility level $R_{1.4}=12.36^{+0.38}_{-0.73}$ km for the radius of a 1.4 solar-mass neutron star, $R_{2.0}=11.96^{+0.94}_{-0.71}$ km for the radius of a 2.0 solar-mass neutron star, $\Lambda_{1.4}=440^{+103}_{-144}$ for the tidal deformability of a 1.4 solar-mass neutron star, and $I_{1.338}=1.425^{+0.074}_{-0.146}\, \times 10^{45}\,\rm{g\,cm}^{2}$ for the moment of inertia of PSR J0737-3039A whose mass is 1.338 solar masses.