Preprint typeset using LATEX style emulateapj v. 12/16/11 AB-INITIO PULSAR MAGNETOSPHERE: THREE-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS OF AXISYMMETRIC PULSARS

We perform “first-principles ” relativistic particle-in-cell simulations of aligned pulsar magneto-sphere. We allow free escape of particles from the surface of a neutron star and continuously populate the magnetosphere with neutral pair plasma to imitate pair production. As pair plasma supply increases, we observe the transition from a charge-separated “electrosphere ” solution with trapped plasma and no spin-down to a solution close to the ideal force-free magnetosphere with electromagnetically-dominated pulsar wind. We calculate the magnetospheric structure, current dis-tribution and spin-down power of the neutron star. We also discuss particle acceleration in the equatorial current sheet. Subject headings: PIC-pulsars: general-stars: magnetic fields-stars: neutron 1