  Soon after the discovery of radio pulsars in 1967, the pulsars are identified
as strongly magnetic (typically $10^{12}$G) rapidly rotating ($\sim 10^{2}-0.1$
Hz) neutron stars. However, the mechanism of particle acceleration in the
pulsar magnetosphere has been a longstanding problem. The central problem is
why the rotation power manifests itself in both gamma-ray beams and a highly
relativistic wind of electron-positron plasmas, which excites surrounding
nebulae observed in X-ray. Here we show with a three dimensional particle
simulation for the global axisymmetric magnetosphere that a steady outflow of
electron-positron pairs is formed with associated pair sources, which are the
gamma-ray emitting regions within the light cylinder. The magnetic field is
assumed to be dipole, and to be consistent, pair creation rate is taken to be
small, so that the model might be applicable to old pulsars such as Geminga.
The pair sources are charge-deficient regions around the null surface, and we
identify them as the outer gap. The wind mechanism is the electromagnetic
induction which brings about fast azimuthal motion and eventually trans-field
drift by radiation drag in close vicinity of the light cylinder and beyond. The
wind causes loss of particles from the system. This maintains charge deficiency
in the outer gap and pair creation. The model is thus in a steady state,
balancing loss and supply of particles. Our simulation implies how the wind
coexists with the gamma-ray emitting regions in the pulsar magnetosphere.
