Gamma-Ray Light Curves from Pulsar Magnetospheres with Finite Conductivity

We investigate the shapes of \gamma-ray pulsar light curves using 3D pulsar magnetosphere models of finite conductivity. These models, covering the entire spectrum of solutions between vacuum and force-free magnetospheres, for the first time afford mapping the GeV emission of more realistic, dissipative pulsar magnetospheres. To this end we generate model light curves following two different approaches: (a) We employ the emission patterns of the slot and outer gap models in the field geometries of magnetospheres with different conductivity \sigma. (b) We define realistic trajectories of radiating particles in magnetospheres of different \sigma and compute their Lorentz factor under the influence of magnetospheric electric fields and curvature radiation-reaction; with these at hand we then calculate the emitted radiation intensity. The light curves resulting from these prescriptions are quite sensitive to the value of \sigma, especially in the second approach. While still not self-consistent, these results are a step forward in understanding the physics of pulsar \gamma-radiation.
Comment: Submitted to the Astrophysical Journal Letters, 15 pages, 4 figures