ON THE SPECTRA AND PULSE PROFILES OF GAMMA-RAY PULSARS

We model spectra and pulse profiles of gamma-ray pulsars assuming that the pulsar's magnetic axis is nearly aligned with its rotation axis. In this model, the nonthermal energy of electrons flowing outward alon g field lines connected to the light cylinder is efficiently converted to gamma rays via magnetic Compton scattering of optical and soft X-r ay photons. The hard photons initiate a pair cascade in the pulsar mag netosphere through magnetic pair production followed by synchrotron em ission. The calculated spectra are used to fit gamma-ray pulsar observ ations. This model produces a hollow cone of emission which can reprod uce both the broad single-peaked and narrow double-peaked pulse profil es observed from gamma-ray pulsars.