Three-dimensional numerical simulations of ambipolar diffusion in NS cores in the one-fluid approximation: instability of poloidal magnetic field
arXiv:2210.10869 · doi:10.1093/mnras/stac3126
Abstract
We numerically model evolution of magnetic fields inside a neutron star under the influence of ambipolar diffusion in the weak-coupling mode in the one-fluid MHD approximation. Our simulations are three-dimensional and performed in spherical coordinates. Our model covers the neutron star core and includes crust where the magnetic field decay is due to Ohmic decay. We discover an instability of poloidal magnetic field under the influence of ambipolar diffusion. This instability develops in the neutron star core and grows on a timescale of 0.2 dimensionless times, reaching saturation by 2 dimensionless times. The instability leads to formation of azimuthal magnetic field with azimuthal wavenumber (at the moment of saturation) which keeps merging and reaches by 16 dimensionless times. Over the course of our simulations (16 dimensionless times) the surface dipolar magnetic field decays, reaching 20 percent of its original value and keeps decaying. The decay timescale for the total magnetic energy is six dimensionless times. The ambipolar diffusion induces electric currents in the crust where these currents dissipate efficiently. Strong electric currents in the crust lead to heating, which could correspond to luminosities of erg s during hundreds of Myrs for an initial magnetic field of G. Ambipolar diffusion leads to formation of small-scale magnetic fields at the neutron star surface.
arXiv commentSubmitted to MNRAS; 26 pages
References in corpus (43)
- Magnetars
- Dedalus: A Flexible Framework for Numerical Simulations with Spectral Methods
- Unifying the observational diversity of isolated neutron stars via magneto-thermal evolution models
- Magneto--thermal evolution of neutron stars
- Magnetohydrodynamics of superfluid and superconducting neutron star cores
- A NICER view of PSR J0030+0451: evidence for a global-scale multipolar magnetic field
- Stability of magnetic fields in non-barotropic stars: an analytic treatment
- Hall Effect in Neutron Star Crusts: Evolution, Endpoint and Dependence on Initial Conditions
- The LUVOIR Mission Concept Study Final Report
- CCOs and the hidden magnetic field scenario
- The influence of Hall drift on the magnetic fields of neutron stars
- Condensed Surfaces of Magnetic Neutron Stars, Thermal Surface Emission, and Particle Acceleration Above Pulsar Polar Caps
- Magnetic, thermal and rotational evolution of isolated neutron stars
- Magnetic field evolution in magnetar crusts through three dimensional simulations
- Magnetic, thermal and rotational evolution of isolated neutron stars
- Magnetically-driven crustquakes in neutron stars
- The Hidden Magnetic Field of The Young Neutron Star in Kesteven 79
- Vortex buoyancy in superfluid and superconducting neutron stars
- Hall equilibria with toroidal and poloidal fields: application to neutron stars
- Hall drift and the braking indices of young pulsars
- Magnetic Field Evolution in Superconducting Neutron Stars
- Magnetic Field Evolution in Neutron Stars: One-Dimensional Multi-Fluid Model
- The relevance of ambipolar diffusion for neutron star evolution
- Simulated magnetic field expulsion in neutron star cores
- 3D modelling of magneto-thermal evolution of neutron stars: method and test cases
- Sleeping beasts: strong toroidal magnetic field in quiescent magnetars explains their large pulsed fraction
- Magnetic Axis Drift and Magnetic Spot Formation in Neutron Stars with Toroidal Fields
- Mechanical Properties of non-accreting Neutron Star Crusts
- Magnetic field evolution and equilibrium configurations in neutron star cores: the effect of ambipolar diffusion
- Forward and inverse cascades in decaying two-dimensional electron magnetohydrodynamic turbulence
- Detection of X-ray Emission from the Very Old Pulsar J0108-1431
- Post fall-back evolution of multipolar magnetic fields and radio pulsar activation
- Powering Central Compact Objects with a Tangled Crustal Magnetic Field
- A possible optical counterpart to the old nearby pulsar J0108-1431
- Cascades in decaying three-dimensional electron magnetohydrodynamic turbulence
- 3D Magneto-thermal Simulations of Tangled Crustal Magnetic Field in Central Compact Objects
- X-ray Emission from Isolated Neutron Stars revisited: 3D magnetothermal simulations
- Two-fluid simulations of the magnetic field evolution in neutron star cores in the weak-coupling regime
- Ages of radio pulsar: long-term magnetic field evolution
- A kinematic study of central compact objects and their host supernova remnants
- Magnetic Field Evolution in Neutron Star Crusts: Beyond the Hall Effect
- On the weak magnetic field of millisecond pulsars: Does it decay before accretion?
- Thermal luminosity degeneracy of magnetized neutron stars with and without hyperon cores