The gamma-ray conversion efficiency of rotation-powered pulsars

We use a new self-consistent model to derive the conversion efficiency from rotation power to gamma-ray power for pulsars (eta(th)). Our result indicates that eta(th)proportional to tau(6/7)P(2), where tau and P are the characteristic age and period of the pulsar, which shows that although the efficiency increases with the characteristic age of the pulsar, it also depends on the pulsar period. We test our model results with the survey of high-energy gamma-rays from pulsars by EGRET. Our model not only successfully explains the efficiency of the confirmed gamma-ray pulsars but also explains why the gamma-ray efficiency of millisecond pulsars is so low.