Observations of TeV gamma rays from the Crab nebula

Abstract

Both the Crab pulsar and nebula have been extensively monitored at all wavelengths from radio bands to high energy γ rays. Satellite experiments on board SAS-II and COS-B, and recently EGRET on board the Compton GRO, were able to detect the pulsar signature up to a few GeV. The radiation from the pulsar appears to dominate over that from the nebula at these energies. Searches for TeV γ-ray emission from the Crab with ground-based telescopes using the atmospheric Cherenkov technique have been conducted during the past three decades. Several marginally significant detections were claimed until the group at Whipple observatory, using the imaging technique, firmly established the Crab nebula as a steady TeV γ-ray source