SIMBAD references

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 approximate scaling laws for the angular momentum loss rate,, where ρ is the density of the interstellar medium, is the Mach number, µ is the star's magnetic moment, Ω_*is its angular velocity and η_mis the magnetic diffusivity. A magnetar with a surface magnetic field of 10¹³-10¹⁵ G is found to spin down to a period P > 10⁵-10⁶ s in ∼10⁴-10⁵ yr. 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-ray repeaters (SGRs) and the isolated neutron star candidate RXJ1856.5-3754.