Power of a Turbulent Pulsar

Abstract

We speculate that stationary force-free pulsar magnetospheres are screw unstable, and the spin-down power of real pulsars is carried by turbulent Poynting jets. The turbulent jet entrains poloidal flux as it propagates away from the star. Due to poloidal flux entrainment, poloidal field inside the jet decreases at a slower rate than the dipole's $r^{-3}$, and the pulsar power increases accordingly: $L\sim (μ^2Ω^4/c^3)(ΩR/c)^{-α}$, where $μ$ is the magnetic dipole, $Ω$ is the frequency, $R$ is the neutron star radius, and $α\lesssim 1$ is an index which depends on spin-dipole angle. Our speculation is of interest because it seems to provide the only possible explanation (without fine-tuning) of observed pulsar braking indices.