Probing nuclear bubble structure via neutron star asteroseismology
arXiv:1609.01802 · doi:10.1093/mnras/stw2575
Abstract
We consider torsional oscillations that are trapped in a layer of spherical-hole (bubble) nuclear structure, which is expected to occur in the deepest region of the inner crust of a neutron star. Because this layer intervenes between the phase of slab nuclei and the outer core of uniform nuclear matter, torsional oscillations in the bubble phase can be excited separately from usual crustal torsional oscillations. We find from eigenmode analyses for various models of the equation of state of uniform nuclear matter that the fundamental frequencies of such oscillations are almost independent of the incompressibility of symmetric nuclear matter, but strongly depend on the slope parameter of the nuclear symmetry energy . Although the frequencies are also sensitive to the entrainment effect, i.e., what portion of nucleons outside bubbles contribute to the oscillations, by having such a portion fixed, we can successfully fit the calculated fundamental frequencies of torsional oscillations in the bubble phase inside a star of specific mass and radius as a function of . By comparing the resultant fitting formula to the frequencies of quasi-periodic oscillations (QPOs) observed from the soft-gamma repeaters, we find that each of the observed low-frequency QPOs can be identified either as a torsional oscillation in the bubble phase or as a usual crustal oscillation, given generally accepted values of for all the stellar models considered here.
References in corpus (34)
- Constraints on the symmetry energy and neutron skins from experiments and theory
- A giant, periodic flare from the soft gamma repeater SGR1900+14
- Discovery of Rapid X-ray Oscillations in the Tail of the SGR 1806-20 Hyperflare
- Gravitational waves and pulsating stars: What can we learn from future observations?
- The Nuclear Symmetry Energy
- Discovery of Fast X-ray Oscillations During the 1998 Giant Flare from SGR 1900+14
- Neutron conduction in the inner crust of a neutron star in the framework of the band theory of solids
- Neutron Star Asteroseismology. Axial Crust Oscillations in the Cowling Approximation
- The 2004 Hyperflare from SGR 1806-20: Further Evidence for Global Torsional Vibrations
- Gravitational wave asteroseismology of fast rotating neutron stars with realistic equations of state
- The symmetry energy at subnuclear densities and nuclei in neutron star crusts
- Torsional Oscillations of Relativistic Stars with Dipole Magnetic Fields
- Signatures of hadron-quark mixed phase in gravitational waves
- Liquid crystals in the mantles of neutron stars
- Density Discontinuity of a Neutron Star and Gravitational Waves
- Probing the Equation of State of Nuclear Matter via Neutron Star Asteroseismology
- Constraints on Neutron Star Crusts From Oscillations in Giant Flares
- Restricting quark matter models by gravitational wave observation
- Upper limits on the observational effects of nuclear pasta in neutron stars
- Effect of superfluidity on neutron star crustal oscillations
- Saturation of nuclear matter and radii of unstable nuclei
- Towards real neutron star seismology: Accounting for elasticity and superfluidity
- Possible Constraints on the Density Dependence of the Nuclear Symmetry Energy from Quasiperiodic Oscillations in Soft Gamma Repeaters
- Magneto-elastic oscillations of neutron stars: exploring different magnetic field configurations
- Spin-Down of Neutron Stars and Compositional Transitions in the Cold Crustal Matter
- Dynamics of the inner crust of neutron stars: hydrodynamics, elasticity and collective modes
- Quasi-Periodic Oscillations in Short Recurring Bursts of the magnetars SGR 1806-20 and SGR 1900+14 Observed With RXTE
- Possible identifications of newly observed magnetar quasi-periodic oscillations as crustal shear modes
- Constraints on Pasta Structure of Neutron Stars from Oscillations in Giant Flares
- Electron screening in the liquid-gas mixed phases of nuclear matter
- Elastic properties of polycrystalline dense matter
- Quasi-periodic oscillations in superfluid, relativistic magnetars with nuclear pasta phases
- Empirical formula of crustal torsional oscillations
- Electron screening effects on crustal torsional oscillations
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- Determination of properties of protoneutron stars toward black hole formation via gravitational wave observations
- Neutron star asteroseismology and nuclear saturation parameter
- On the Persistence of QPOs During the SGR 1806-20 Giant Flare
- Probing crustal structures from neutron star compactness
- Gravitational wave asteroseismology for low-mass neutron stars
- Searching for quasi-periodic oscillations in astrophysical transients using Gaussian processes
- Light curves from highly compact neutron stars with spot size effect
- Unified nuclear matter EOSs constrained by the in-medium balance in density-dependent covariant density functionals
- Estimating the nuclear saturation parameter via low-mass neutron star asteroseismology
- Gravitational wave asteroseismology on cooling neutron stars
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- Magnetar QPOs and neutron star crust elasticity
- Stability of the protoneutron stars toward black hole formation
- Universality in supernova gravitational waves with proto-neutron star properties
- Emergence of new oscillation modes in dark matter admixed neutron stars
- Shear and interface modes in neutron stars with pasta structures
- Shear oscillations in neutron stars and the nuclear symmetry energy
- Universality in quasinormal modes of neutron stars with quark-hadron crossover
- Probing the impact of Delta-Baryons on Nuclear Matter and Non-Radial Oscillations in Neutron Stars
- General relativistic surface degrees of freedom in perturbed hybrid stars
- Quark matter with strong magnetic field and possibility of the third family of compact stars
- Accuracy of one-dimensional approximation in neutron star quasi-normal modes
- Universal relation involving fundamental modes in two-fluid dark matter admixed neutron stars
- Effects of finite sizes of atomic nuclei on shear modulus and torsional oscillations in neutron stars
- Nuclear pasta structures at high temperatures
- Selfsimilarity relations for torsional oscillations of neutron stars
- Effects of multidimensional treatment of gravity in simulations on supernova gravitational waves
- Gravitational wave asteroseismology of accreting neutron stars in a steady state
- Zeeman splitting of torsional oscillation frequencies of magnetars
- Nuclear masses and the equation of state of nuclear matter
- Powerful flares and magneto-elastic oscillations of magnetars
- Universal relations between the quasinormal modes of neutron stars and magnetic tidal deformability
- The -mode frequencies in cold neutron stars and nuclear saturation parameters
- Universality of dual mass-scaled fundamental modes in two-fluid neutron stars with mirror dark matter
- Zeeman effect in oscillations of magnetars with toroidal magnetic fields