Gamma-ray curvature radiation from the polar regions of a radio pulsar with an axisymmetric magnetic field

The influence of an axisymmetric magnetic field on the intensity, spectrum, and shape of a pulse of gamma-ray curvature radiation from the polar regions of a radio pulsar is investigated. The pulsar is considered in a Goldreich-Julian model with a free-electron emission from the neutron-star surface. The influence on the curvature radiation of variations of both the curvature of the magnetic field lines and the electric field due to the nondipolarity of the magnetic field are investigated. The presence of even modest nondipolarity (less than 10%) can lead to a sharp drop in the intensity of the gamma-ray curvature radiation, while the intensity of the X-ray curvature radiation (photon energies <100 keV) is affected only weakly.