The outer crust of a cold, non-accreting neutron star within the Quark-Meson Coupling (QMC) model

Abstract

The outer crust properties of cold non-accreting neutron stars are studied within the framework of the quark-meson coupling (QMC) model, which includes the effects of modifications of the quark structure inside individual nucleons when they are within a high-density nuclear medium. With a unique set of five well-constrained adjustable parameters, which have a clear physical basis, the QMC model gives predictions for the ground state observables of even-even nuclei which agree with experiment as well as traditional models. Furthermore, it gives improved theoretical values for nuclei thought to play a role in the outer crusts of neutron stars but for which experimental data is not available. Using the latest experimental data tables wherever possible but otherwise the predictions from the QMC model, we construct an equation of state for the outer crust which is then used within stellar model calculations to obtain an equilibrium sequence of crustal layers, each characterized by a particular neutron rich nuclei. Various properties of the layers are calculated for a range of neutron-star masses, and comparisons are made with alternative equations of state from the literature. This leads to the conclusion that the QMC model successfully predicts the outer crust properties and is fully comparable with the more traditional mass models, which all depend on a larger number of parameters.

Minor changes in the text (typos and phrasing), additional cross-listing, 35 pages, 7 figures

References in corpus (13)

• 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
• The Skyrme Interaction in finite nuclei and nuclear matter
• Cold uniform matter and neutron stars in the quark-mesons-coupling model
• Databases and tools for nuclear astrophysics applications BRUSsels Nuclear LIBrary (BRUSLIB), Nuclear Astrophysics Compilation of REactions II (NACRE II) and Nuclear NETwork GENerator (NETGEN)
• The physics of neutron stars
• Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
• The pasta phase within density dependent hadronic models
• Neutron drip transition in accreting and nonaccreting neutron star crusts
• Metastability of hadronic compact stars
• Crystallization of the outer crust of a non-accreting neutron star
• Binary and ternary ionic compounds in the outer crust of a cold nonaccreting neutron star
• Tensor and pairing interactions within the QMC energy density functional

Cited by in corpus (3)

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