Gamma-ray astronomy from the ground -- future perspectives

TL;DR

This paper discusses the future of ground-based gamma-ray astronomy, highlighting new instrumentation, major upcoming projects like CTAO and SWGO, and emerging concepts to enhance performance across the gamma-ray energy spectrum.

Contribution

It provides a comprehensive overview of upcoming projects, instrumentation developments, and future concepts shaping the next decades of ground-based gamma-ray astronomy.

Findings

CTA and SWGO will dominate the next decade's gamma-ray observations.

Emerging instrumentation concepts aim to improve performance across energy ranges.

Complementary approaches like particle detector arrays and Cherenkov telescopes are essential.

Abstract

I provide a personal perspective on the future of the field of ground-based gamma-ray astronomy, on the occasion of the 2024 {\it Gamma} conference in Milan. I discuss some of the scientific motivations for new instrumentation and the major new projects that are in development or already under construction, together with emerging concepts for instrumentation in the farther future. I stress the strong complementarity of the ground-level particle detector arrays, with their wide-field capabilities, and the more precise Cherenkov telescope arrays. The key science topics for the next decades require both approaches and both are developing rapidly towards major performance advances and full sky coverage. I will briefly outline the status and roles of the projects CTAO and SWGO which will dominate the next decade. Beyond these projects are several developments which might boost performance at both ends of the ground-based gamma-ray energy range, including the plenoscope approach at low energies and diverse approaches to ultra-high-energy gamma-ray astronomy; from lake-based instruments to arrays of very small Cherenkov telescopes. I will again briefly review these activities and how they may contribute long term.