Characteristics of extensive air showers around the energy threshold for ground-particle-based gamma-ray observatories

Abstract

Very high energy gamma-ray astronomy based on the measurement of air shower particles at ground-level has only recently been established as a viable approach, complementing the well established air Cherenkov technique. This approach requires high (mountain) altitudes and very high surface coverage particle detectors. While in general the properties of air showers are well established for many decades, the extreme situation of ground-level detection of very small showers from low energy primaries has not yet been well characterised for the purposes of gamma-ray astronomy. Here we attempt such a characterisation, with the aim of supporting the optimisation of next-generation gamma-ray observatories based on this technique. We address all of the key ground level observables and provide parameterisations for use in detector optimisation for shower energies around 1 TeV. We emphasise two primary aspects: the need for large area detectors to effectively measure low-energy showers, and the importance of muon identification for the purpose of background rejection.

This is a pre-print of an article published in EPJC. The final authenticated version is available online at: https://doi.org/10.1140/epjc/s10052-019-6942-x

References in corpus (2)

• Observations of the Crab Nebula with H.E.S.S
• The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

Cited by in corpus (5)

• A Double Layered Water Cherenkov Detector Array for Gamma-Ray Astronomy
• The Mercedes water Cherenkov detector
• Muons as a tool for background rejection in Imaging Atmospheric Cherenkov Telescope arrays
• Detecting gamma-rays with moderate resolution and large field of view: Particle detector arrays and water Cherenkov technique
• Health threat from cosmic radiation during a manned mission to Mars