Search for pulsed γ-ray emission from radio pulsars in the COS-B data.

Pulsed gamma-ray emission from radio pulsars has been sought in a study of pulsar parameters for 145 radio observations, contemporary with gamma-ray observations, by the COS-B spacecraft. No signal has been detected in the 50 MeV-2 GeV energy range of the study, either globally or from individual pulsars. These results indicate that the average product of the conversion efficiency from the pulsar braking power into gamma-rays, and the pulsar moment of inertia, cannot exceed 6 x 10 to the 43rd g/sq cm, for pulsar ages greater than 40,000 years. This implies that the contribution of old pulsars to the observed galactic gamma-ray emission is less than 5 percent for gamma-ray energies greater than 50 MeV.