The Prospects for Very High Energy Gamma Ray Astronomy

Abstract

Very-high-energy (VHE) gamma rays, with energies .<: 1 TeV = 1012 eV, are observed with ground-based telescopes using the atmospheric Cerenkov technique. This field of astronomy has recently experienced its coming of age, opening a new observational window on the universe after efforts spanning almost 30 years. Recent advances in this field have been aided by the results from satellite detectors with high-energy (HE) gamma ray 'eyes'. Satellite detectors are sensitive to HE gamma rays, up to energies of about 10 GeV = 1010 eV. In this paper, VHE gamma ray astronomy is reviewed, and the 3·8 m diameter telescope of the Japanese-Australian CANGAROO project is used to illustrate the detection techniques. As VHE gamma ray astronomy is closely related to observations in the HE region, results from recent satellite experiments are also discussed.