Gamma-Ray Astronomy from the Ground

TL;DR

Ground-based gamma-ray astronomy uses air shower detection to explore high-energy cosmic phenomena, revealing insights into astrophysical processes and fundamental physics, with new advanced instruments on the horizon.

Contribution

This paper reviews the current state of ground-based gamma-ray astronomy and discusses upcoming instruments and future prospects in the field.

Findings

Successful detection of gamma-ray sources using imaging air Cherenkov technique

Probing particle acceleration and high-energy physics beyond the standard model

Development of next-generation ground-based gamma-ray instruments

Abstract

The observation of cosmic gamma-rays from the ground is based upon the detection of gamma-ray initiated air showers. At energies between approximately $10^{11}$ eV and $10^{13}$ eV, the imaging air Cherenkov technique is a particularly successful approach to observe gamma-ray sources with energy fluxes as low as $\approx 10^{-13}$ erg\,cm$^{-2}\,$s$^{-1}$. The observations of gamma-rays in this energy band probe particle acceleration in astrophysical plasma conditions and are sensitive to high energy phenomena beyond the standard model of particle physics (e.g., self-annihilating or decaying dark matter, violation of Lorentz invariance, mixing of photons with light pseudo-scalars). The current standing of the field and its major instruments are summarised briefly by presenting selected highlights. A new generation of ground based gamma-ray instruments is currently under development. The perspectives and opportunities of these future facilities will be discussed.