data of inadequate spatial resolution and less plausible physical assumptions.
author:
- 'D. J. Helfand, E. V. Gotthelf, & J. P. Halpern'
title: The Vela Pulsar and its Synchrotron Nebula
---

Introduction
============

Within two years of the discovery of radio pulses from CP1919+21, magnetized, rotating neutron stars were firmly established as the origin of these remarkable signals. Furthermore, the steady increase in pulse period recorded for all sources provided an explanation for the pulsar power source: rotational kinetic energy. The detection of a decelerating 33 msec pulsar in the Crab Nebula solved the long-standing mystery of what powered this unique nebula: the spin-down rate of the Crab pulsar implied an energy loss rate, $\dot E \sim 5 \times 10^{38}$ erg s$^{-1}$, more than enough to cover the radiation losses observed from radio to gamma ray frequencies. By 1974, the basic model of the electrodynamics of pulsar magnetospheres and their coupling to the surrounding synchrotron-emitting plasma was in place (Rees and Gunn 1974), although a detailed understanding of the processes involved continues to elude us (e.g., Arons 1998).

After a decade of timing observations, it became clear that most pulsars were not defect-free clocks which simply slowed smoothly as rotational 