Whipple Telescope observations of potential TeV γ-ray sources found by the Tibet Air Shower Array

Abstract

An all-sky survey performed with the Tibet Air Shower Array (Tibet AS) has found a number of potential point sources of TeV γ rays. If they are steady sources, the implied Tibet AS fluxes should be visible with strong significance to the Whipple 10-m γ-ray telescope ( E>400 GeV) with only a short (5 h) exposure. We have observed four candidate directions from the Tibet-II HD dataset for ∼5 h, each with the Whipple telescope. In addition, we observed a new candidate direction from the Tibet-III Phase 1 dataset for 7.5 h. We have found no corresponding excesses at the flux levels implied, and we have set upper limits for each candidate.