A Model for the X-Ray Luminosity of Pulsar Nebulae

Abstract

A one-zone, shocked windmodel is developed for the X-ray luminosity of pulsar nebulae. Ifthe electrons and positrons cool rapidly by synchrotron radiationand the initial particle spectrum is similar to that of the CrabNebula, the X-ray luminosity is produced from the pulsar power withhigh efficiency and is insensitive to the model parameters. If theelectrons are not in the cooling regime, the X-ray luminosity is producedwith lower efficiency, as appears to be the case for the compactnebula around the Vela pulsar. The observed X-ray spectral index is anindicator for which case applies and thus plays a role in estimatingthe pulsar power needed to produce an observed X-ray luminosity.