Spinning-Down of Moving Magnetars in the Propeller Regime

Abstract

We use axisymmetric magnetohydrodynamic simulations to investigate the spinning-down of magnetars rotating in the propeller regime and moving supersonically through the interstellar medium. The simulations indicate that magnetars spin-down rapidly due to this interaction, faster than for the case of a non-moving star. From many simulation runs we have derived an approximate scaling laws for the angular momentum loss rate, \dot{L} \propto \~η_m^{0.3}μ^{0.6}ρ^{0.8}{\cal M}^{-0.4} Ω_*^{1.5}, where ρis the density of the interstellar medium, \cal M is Mach number, μis the star's magnetic moment, Ω_* is its angular velocity, and η_m is magnetic diffusivity. A magnetar with a surface magnetic field of 10^{13} - 10^{15} G is found to spin-down to a period P > 10^5-10^6 s in \sim 10^4 - 10^5 years. There is however uncertainty about the value of the magnetic diffusivity so that the time-scale may be longer. We discuss this model in respect of Soft Gamma Repeaters (SGRs) and the isolated neutron star candidate RXJ1856.5-3754.

arXiv comment10 pages, 4 figures, accepted by MNRAS. See version with better resolution figures and animation at http://astrosun2.astro.cornell.edu/us-rus/propeller.htm

References in corpus (18)

• A giant, periodic flare from the soft gamma repeater SGR1900+14
• Discovery of a magnetar associated with the Soft Gamma Repeater SGR 1900+14
• The Discovery of an Anomalous X-ray Pulsar in the Supernova Remnant Kes 73
• The thermal radiation of the isolated neutron star RX J1856.5-3754 observed with Chandra and XMM-Newton
• The Propeller Regime of Disk Accretion to a Rapidly Rotating Magnetized Star
• Period clustering of the Anomalous X-ray Pulsars and magnetic field decay in magnetars
• RX J1856-3754: Evidence for a Stiff EOS
• Accretion Onto Fast X-Ray Pulsars
• Propeller-driven Outflows and Disk Oscillations
• Magnetic propeller outflows
• MHD Simulations of Bondi Accretion to a Star in the "Propeller" Regime
• Propagation of Magnetized Neutron Stars Through the Interstellar Medium
• Spherical Bondi accretion onto a magnetic dipole
• Isolated magnetar spin-down, soft X-ray emission and RXJ1856.5-3754
• Winds, B-Fields, and Magnetotails of Pulsars
• Supersonic propeller spindown of neutron stars in wind-fed mass-exchange close binaries
• Magnetically Accreting Isolated Old Neutron Stars
• Implications of the Narrow Period Distribution of Anomalous X-ray Pulsars and Soft Gamma-Ray Repeaters

Cited by in corpus (6)

• Are There Magnetars in High Mass X-ray Binaries? The Case of SuperGiant Fast X-Ray Transients
• Magnetic Hydrogen Atmosphere Models and the Neutron Star RX J1856.5-3754
• Towards a unified view of inhomogeneous stellar winds in isolated supergiant stars and supergiant high mass X-ray binaries
• Bondi-Hoyle Accretion onto Magnetized Neutron Star
• Modelling the bow shock Pulsar Wind Nebulae propagating through a non-uniform ISM
• Submillimetre observations of RX J1856.5--3754