The Gamma-ray Cherenkov Telescope for the Cherenkov Telescope Array

TL;DR

The paper discusses the design, development, and initial testing of the Gamma-ray Cherenkov Telescope (GCT), a key component of the Cherenkov Telescope Array aimed at high-energy gamma-ray observation.

Contribution

It introduces the GCT design featuring dual-mirror optics and prototype testing results, advancing the development of CTA's small-sized telescopes.

Findings

First Cherenkov images recorded with GCT prototype

Successful development of dual-mirror Schwarzschild-Couder optics

Progress in silicon photomultiplier camera prototype

Abstract

The Cherenkov Telescope Array (CTA) is a forthcoming ground-based observatory for very-high-energy gamma rays. CTA will consist of two arrays of imaging atmospheric Cherenkov telescopes in the Northern and Southern hemispheres, and will combine telescopes of different types to achieve unprecedented performance and energy coverage. The Gamma-ray Cherenkov Telescope (GCT) is one of the small-sized telescopes proposed for CTA to explore the energy range from a few TeV to hundreds of TeV with a field of view $\gtrsim 8^\circ$ and angular resolution of a few arcminutes. The GCT design features dual-mirror Schwarzschild-Couder optics and a compact camera based on densely-pixelated photodetectors as well as custom electronics. In this contribution we provide an overview of the GCT project with focus on prototype development and testing that is currently ongoing. We present results obtained during the first on-telescope campaign in late 2015 at the Observatoire de Paris-Meudon, during which we recorded the first Cherenkov images from atmospheric showers with the GCT multi-anode photomultiplier camera prototype. We also discuss the development of a second GCT camera prototype with silicon photomultipliers as photosensors, and plans toward a contribution to the realisation of CTA.