Conceptual design of a next-generation all-sky γ-ray telescope operating at TeV energies

Abstract

The next generation all-sky monitor operating at TeV (0.1–30 TeV) energies should be capable of performing a continuous high sensitivity sky survey, and detecting transient sources, such as AGN flares, with high statistical significance on timescales of hours to days. We describe an instrument concept for a large area, wide aperture, TeV ground-based γ-ray telescope. The conceptual design is comprised of ∼ 20 000 1 m 2 scintillator-based pixels arranged in a densely packed mosaic. In addition to fast timing, the dense array of pixels also provides a unique imaging capability; the shower image, the spatial distribution of secondary particles at ground level, can be exploited to identify and reject hadronic backgrounds. The good angular resolution and background rejection capabilities lead directly to high sensitivity, while retaining a large field of view, large effective area, and high duty cycle. An instrument such as the one described here complements the narrow field of view air-Cherenkov telescopes and could, in conjunction with future space-based instruments, extend the energy range for continuous monitoring of the γ-ray sky from MeV through TeV energies.