Determination of the symmetry energy from the neutron star equation of state

Abstract

We analyze the uncertainties introduced in the determination of the neutron star matter proton fraction, in a range of densities close to the saturation density, if the cold $\beta$-equilibrium neutron star matter equation of state (EoS) is known. In particular, we discuss the effect of neglecting the muon contribution and of considering that the energy density of nuclear matter is well described by taking only terms until second order in the proton-neutron asymmetry. It is shown that two types of uncertainties may be associated with the extraction of the symmetry energy from the $\beta$-equilibrium equation of state: an overestimation if terms above the parabolic approximation on the asymmetry parameter are neglected, or an underestimation if the muon contribution is not considered. The effect of the uncertainty on the symmetric nuclear matter EoS on the determination of the proton fraction is discussed. It could be shown that the neutron star mass-radius curve is sensitive to the parabolic approximation on the asymmetry parameter.

13 pages, 8 figures, published version

References in corpus (21)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Shapiro delay measurement of a two solar mass neutron star
• A Massive Pulsar in a Compact Relativistic Binary
• Multi-messenger Observations of a Binary Neutron Star Merger
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
• A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• Refined Mass and Geometric Measurements of the High-Mass PSR J0740+6620
• GW170817: Joint Constraint on the Neutron Star Equation of State from Multimessenger Observations
• Implications of PREX-II on the equation of state of neutron-rich matter
• Progress in Constraining Nuclear Symmetry Energy Using Neutron Star Observables Since GW170817
• Density dependence of the nuclear symmetry energy: a microscopic perspective
• Astrophysical Constraints on the Symmetry Energy and the Neutron Skin of ${}^{208}$Pb with Minimal Modeling Assumptions
• New equations of state constrained by nuclear physics, observations, and QCD calculations of high-density nuclear matter
• Strong correlations of neutron star radii with the slopes of nuclear matter incompressibility and symmetry energy at saturation
• Relativistic hypernuclear compact stars with calibrated equations of state
• Thermal evolution of relativistic hyperonic compact stars with calibrated equations of state
• Neutron stars with large quark cores
• Constraints on high density equation of state from maximum neutron star mass
• Empirical constraints on the high-density equation of state from multi-messenger observables

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