Survey of candidate gamma-ray sources at TeV energies using a high-resolution Cerenkov imaging system - 1988-1991

The steady TeV gamma-ray emission from the Crab Nebula has been used to optimize the sensitivity of the Whipple Observatory atmospheric Cerenkov imaging telescope. Using this method, which is of order 20 times more sensitive than the standard method using a simple non-imaging detector, it is possible to detect the Crab Nebula at a significance level in excess of 6 standard deviations (6 σ) in under 1 hr on source (with a corresponding time observing a background comparison region); a source one-tenth the strength of the Crab Nebula can be detected at the 4 σ level after 40 hr on the source (and 40 hr on a background region)