Effects of inner crusts on $g$-mode oscillations in neutron stars

Abstract

In this work we investigate the influence of neutron stars' crusts on the non-radial $g$-mode oscillations and examine their correlations with nuclear matter properties fixed by adopting 10 different relativistic density functionals. At subsaturation densities, neutron star matter takes non-uniform structures and form the crusts. We find that the Brunt-Väisälä (BV) frequency increases significantly at densities slightly above the neutron drip density (i.e., neutron stars' inner crusts), which leads to crust $g$-mode oscillations with their frequencies insensitive to the adopted density functional. At larger densities, BV frequency increases as well due to the core-crust transitions and emergence of muons, which lead to core $g$-mode oscillations. It is found that the obtained core $g$-mode frequencies generally increase with the slope of nuclear symmetry energy $L$, which eventually intersect with that of the crust $g$ modes adopting large enough $L$. This leads to the avoid-crossing phenomenon for the global $g$ modes that encompass contributions from both the crust and core. The correlation between the global $g_1$ mode and $L$ is identified for neutron stars with masses $M\gtrsim 1.4M_{\odot }$, which enables the measurements of $L$ based on gravitational wave observations. In our future study, the effects of the discontinuities in density or shear modulus should be considered, while the temperature, rotation, magnetic field, and superfluid neutron gas in neutron stars could also play important roles.

References in corpus (39)

• A Massive Pulsar in a Compact Relativistic Binary
• 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
• Exploring the Sensitivity of Next Generation Gravitational Wave Detectors
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• Relativistic Continuum Hartree Bogoliubov Theory for Ground State Properties of Exotic Nuclei
• Accurate Determination of the Neutron Skin Thickness of ${}^{208}$Pb through Parity-Violation in Electron Scattering
• Exotic modes of excitation in atomic nuclei far from stability
• Relativistic Mean-Field Hadronic Models under Nuclear Matter Constraints
• Precision Determination of the Neutral Weak Form Factor of ${}^{48}$Ca
• A NICER View of the Nearest and Brightest Millisecond Pulsar: PSR J0437$\unicode{x2013}$4715
• An updated mass-radius analysis of the 2017-2018 NICER data set of PSR J0030+0451
• Astrophysical Constraints on the Symmetry Energy and the Neutron Skin of ${}^{208}$Pb with Minimal Modeling Assumptions
• Pulsars as Astrophysical Laboratories for Nuclear and Particle Physics
• The Dipole Magnetic Field and Spin-down Evolutions of The High Braking Index Pulsar PSR J1640-4631
• A NICER View of PSR J1231$-$1411: A Complex Case
• Resonant Tidal Excitation of Oscillation Modes in Merging Binary Neutron Stars: Inertial-Gravity Modes
• Universal Relations for Neutron Star F-Mode and G-Mode Oscillations
• Radial and Nonradial Oscillation Modes in Rapidly Rotating Stars
• Dynamical tides in coalescing superfluid neutron star binaries with hyperon cores and their detectability with third generation gravitational-wave detectors
• Accuracy of relativistic Cowling approximation in protoneutron star asteroseismology
• $g$-modes of neutron stars with hadron-to-quark crossover transitions
• Unified neutron star EOSs and neutron star structures in RMF models
• Thermal Properties of Asymmetric Nuclear Matter
• Quasi-normal g-modes of neutron stars with quarks
• Systematic study on the quark-hadron mixed phase in compact stars
• Constraining equation of state groups from $g$-mode asteroseismology
• Oscillation Modes and Gravitational Waves from Strangeon Stars
• g-mode Oscillations in Neutron Stars with Hyperons
• BCS-BEC crossover in nuclear matter with the relativistic Hartree-Bogoliubov theory
• Gravitational wave asteroseismology on cooling neutron stars
• Unified nuclear matter EOSs constrained by the in-medium balance in density-dependent covariant density functionals
• Probing phase transition in neutron stars via the crust-core interfacial mode
• Temperature Effects on Core g-modes of Neutron Stars
• Radial and Non-Radial Oscillations of Inverted Hybrid Stars
• Shear oscillations in neutron stars and the nuclear symmetry energy
• Non-radial oscillations and gravitational wave emission of hybrid neutron stars
• The impact of nuclear reactions on the neutron-star g-mode spectrum
• $g$-mode of neutron stars in pseudo-Newtonian gravity

Cited by in corpus (3)

• Nonradial oscillations of stratified neutron stars with solid crusts: Mode characterization and tidal resonances in coalescing binaries
• Suppression of composition $g$-modes in chemically-equilibrating warm neutron stars
• Properties and microscopic structures of dense stellar matter in RMF models