Search for pulsed γ-ray emission from radio pulsars in the COS-B data.
Caraveo, P. A.; Bignami, G. F.; Strong, A. W.; Hermsen, W.; Masnou, J. L.; Manchester, R. N.; Bennett, K.; Buccheri, R.; Kanbach, G.; Mayer-Hasselwander, H. A.; Paul, J. A.; Scarsi, L.; Sacco, B.; Bloemen, J. B. G. M.; Boriakoff, V.; Özel, M. E.
Italy, Netherlands, United States, Germany, Australia, France
Abstract
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.