The Gamma-ray Cherenkov Telescope (GCT) is one of the telescopes proposed for the Small Sized Telescope (SST) section of CTA. Based on a dual-mirror Schwarzschild-Couder design, which allows for more compact telescopes and cameras than the usual single-mirror designs, it will be equipped with a Compact High-Energy Camera (CHEC) based on silicon photomultipliers (SiPM). In 2015, the GCT prototype was the first dual-mirror telescope constructed in the prospect of CTA to record Cherenkov light on the night sky. Further tests and observations have been performed since then. This report describes the current status of the GCT, the results of tests performed to demonstrate its compliance with CTA requirements, and the optimisation of the design for mass production. The GCT collaboration, including teams from Australia, France, Germany, Japan, the Netherlands and the United Kingdom, plans to install the first telescopes on site in Chile for 2019-2020 as part of the CTA pre-production phase.
The GCT (Gamma-ray Cherenkov Telescope) is a dual-mirror prototype of Small-Sized-Telescopes proposed for the Cherenkov Telescope Array (CTA) and made by an Australian-Dutch-French-German-Indian-Japanese-UK-US consortium. The integration of this end-to-end telescope was achieved in 2015. On-site tests and measurements of the first Cherenkov images on the night sky began on November 2015. This contribution describes the telescope and plans for the pre-production and a large scale production within CTA.
The Gamma-ray Cherenkov Telescope (GCT) is proposed for the Small-Sized Telescope component of the Cherenkov Telescope Array (CTA). GCT's dual-mirror Schwarzschild-Couder (SC) optical system allows the use of a compact camera with small form-factor photosensors. The GCT camera is ~ 0:4 m in diameter and has 2048 pixels; each pixel has a ~ 0:2° angular size, resulting in a wide field-of-view. The design of the GCT camera is high performance at low cost, with the camera housing 32 front-end electronics modules providing full waveform information for all of the camera's 2048 pixels. The first GCT camera prototype, CHEC-M, was commissioned during 2015, culminating in the first Cherenkov images recorded by a SC telescope and the first light of a CTA prototype. In this contribution we give a detailed description of the GCT camera and present preliminary results from CHEC-M's commissioning.
The Cherenkov Telescope Array (CTA) is an international collaboration that aims to create the world's foremost very high energy gamma-ray observatory, composed of large, medium and small size telescopes (SST). The SSTs will be the most numerous telescopes on site and will focus on capturing the rarer highest energy photons. Three prototypes of SST are designed and currently under construction; two of them, ASTRI and SST-GATE, have been designed, based on a dual-mirror Schwarzschild-Couder (SC) design which has never been built before for any astronomical observation. The SC optical design allows for a small plate scale, a wide field of view and a lightweight cameras aiming to minimize the cost of SST telescopes in order to increase their number in the array.
The aim of this article is to report the progress of the two telescope projects prototyping telescope structures and cameras for the Small Size Telescopes for CTA. After a discussion of the CTA project and its scientific objectives, the performance of the SC design is described, with focus on the specific designs of SST-GATE and ASTRI telescopes. The design of both prototypes and their progress is reported in the current prototyping phase. The designs of Cherenkov cameras, CHEC and ASTRI, to be mounted on these telescopes are discussed and progresses are reported.
The Cherenkov Telescope Array (CTA) is an international collaboration that aims to create the world's
largest (ever) Very High Energy gamma-ray telescope array, consisting of more than 100 telescopes
covering an area of several square kilometers to observe the electromagnetic showers generated by
incoming cosmic gamma-rays with very high energies (from a few tens of GeV up to over 100 TeV).
Observing such sources requires - amongst many other things - a large FoV (Field of View). In the
framework of CTA, SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) aims to
investigate and to build one of the two first CTA prototypes based on the Schwarzschild-Couder (SC)
optical design that delivers a FoV close to 10 degrees in diameter. To achieve the required
performance per unit cost, many improvements in mirror manufacturing and in other technologies are
required. We present in this paper the current status of our project. After a brief introduction of the
very high energy context, we present the opto-mechanical design, discuss the technological tradeoffs
and explain the electronics philosophy that will ensure the telescopes cost is minimised without
limiting its capabilities. We then describe the software nedeed to operate the telescope and conclude
by presenting the expected telescope performance and some management considerations.
In the last two decades a new window for ground-based high energy astrophysics has been opened. This explores the
energy band from about 100 GeV to 10 TeV by making use of Imaging Atmospheric Cherenkov Telescopes (IACTs).
Research in Very High Energy (VHE) gamma-ray astronomy is progressing rapidly and, thanks to the newest facilities
such as MAGIC, HESS and VERITAS, astronomers and particle physicists are obtaining data with far-reaching
implications for theoretical models.
The Cherenkov Telescope Array (CTA) is the ambitious international next-generation facility for gamma-ray astronomy
and astrophysics that aims to provide a sensitivity of a factor of 10 higher than current instruments, extend the energy
band coverage from below 50 GeV to above 100 TeV, and improve significantly the energy and angular resolution to
allow precise imaging, photometry and spectroscopy of sources. To achieve this, an extended array composed of nearly
100 telescopes of large, medium and small dimensions is under development. Those telescopes will be optimized to
cover the low, intermediate and high energy regimes, respectively.
In this paper, we focus our attention on the Small Size Telescopes (SSTs): these will be installed on the CTA southern
hemisphere site and will cover an area of up to 10 km2. The energy range over which the SSTs will be sensitive is from
around 1 TeV to several hundreds of TeV. The status of the optical and mechanical designs of these telescopes is
presented and discussed. Comments are also made on the focal surface instruments under development for the SSTs.