Relativistic force-free electrodynamic simulations of neutron star magnetospheres

The luminosity and structure of neutron star magnetospheres are crucial to our understanding of pulsar and plerion emission. A solution found using the force-free approximation would be an interesting standard with which any model with more physics could be compared. Prior quasi-analytic force-free solutions may not be stable, while prior time-dependent magnetohydrodynamic models used unphysical model parameters. We use a time-dependent relativistic force-free electrodynamics code with no free parameters to find a unique stationary solution for the axisymmetric rotating pulsar magnetosphere in a Minkowski space-time in the case of no surface currents on the star. The solution is similar to the force-free quasi-analytic solution found in 1999 by Contopoulos, Kazanas & Fendt and the numerical magnetohydrodynamic solution found in 2006 by Komissarov. The magnetosphere structure and the usefulness of the classical y-point in the general dissipative regime are discussed. The pulsar luminosity is found to be L approximate to 0.99 +/- 0.01 mu(2)Omega(4)(star)/c(3) for a dipole moment mu and stellar angular frequency Omega(star).