Constraints on the symmetry energy from neutron star observations

Abstract

The modeling of many neutron star observables incorporates the microphysics of both the stellar crust and core, which is tied intimately to the properties of the nuclear matter equation of state (EoS). We explore the predictions of such models over the range of experimentally constrained nuclear matter parameters, focusing on the slope of the symmetry energy at nuclear saturation density $L$. We use a consistent model of the composition and EoS of neutron star crust and core matter to model the binding energy of pulsar B of the double pulsar system J0737-3039, the frequencies of torsional oscillations of the neutron star crust and the instability region for r-modes in the neutron star core damped by electron-electron viscosity at the crust-core interface. By confronting these models with observations, we illustrate the potential of astrophysical observables to offer constraints on poorly known nuclear matter parameters complementary to terrestrial experiments, and demonstrate that our models consistently predict $L<70$ MeV.

11 pages, 5 figures, talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS)

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• Nuclear symmetry energy probed by neutron skin thickness of nuclei
• Constraints on the symmetry energy and on neutron skins from the pygmy resonances in 68Ni and 132Sn
• Symmetry Energy I: Semi-Infinite Matter
• Neutron and Proton Transverse Emission Ratio Measurements and the Density Dependence of the Asymmetry Term of the Nuclear Equation of State
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• Neutron Star Asteroseismology. Axial Crust Oscillations in the Cowling Approximation
• Neutron skin thickness in droplet model with surface width dependence: indications of softness of the nuclear symmetry energy
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• Constraints on Neutron Star Crusts From Oscillations in Giant Flares
• Nuclear symmetry energy at subnormal densities from measured nuclear masses
• Nuclear matter symmetry energy and the symmetry energy coefficient in the mass formula
• Density dependence of nuclear symmetry energy constrained by mean-field calculations
• The Formation of the Double Pulsar PSR J0737-3039A/B

Cited by in corpus (6)

• Thermodynamics of isospin-asymmetric nuclear matter from chiral effective field theory
• Possible Constraints on the Density Dependence of the Nuclear Symmetry Energy from Quasiperiodic Oscillations in Soft Gamma Repeaters
• Viscosity of neutron star matter and $r$-modes in rotating pulsars
• The cooling of the Cassiopeia A neutron star as a probe of the nuclear symmetry energy and nuclear pasta
• Constraining the density dependence of the nuclear symmetry energy from an X-ray bursting neutron star
• Self consistent calculation of the nuclear composition in hot and dense stellar matter