The Crab Nebula at high energies - A historical perspective

The Crab Nebula, the remnant of a nearby supernova in 1054, exhibits many phenomena of interest to high energy astrophysicists. The featureless optical continuum in the central region emits X-rays and gamma-ray energy with a spectrum possibly extending to 10(12) eV. This emission is believed due to the synchrotron radiation of relativistic electrons in a 6 x10(-4) gauss nebular field, which are still being accelerated. The nebula is apparently powered by the spin-down of the 33 ms rotating neutron star near the center of the nebula. This pulsar emits radiation over the entire radio, optical, X-ray and gamma-ray range. Although most of the basic discoveries were made in the 1960's and 1970's, recent data from ground based observatories, the Hubble Telescope, and the Compton Gamma Ray Observatory are providing significant new details of processes in the Crab.