Design Concepts for the Cherenkov Telescope Array (1008.3703v3)

Abstract: Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV to 10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.

• The paper introduces CTA's design that achieves a 5-10 fold improvement in gamma-ray sensitivity over existing instruments.
• It details the use of large, medium, and small telescopes to cover a wide energy range from below 100 GeV to above 100 TeV.
• The design incorporates an open observatory model and robust data management strategies to foster global collaboration in high-energy astrophysics.

Overview of Cherenkov Telescope Array (CTA) Design Concepts

The paper presents the foundational design concepts and objectives for the Cherenkov Telescope Array (CTA), a proposed advanced facility in gamma-ray astronomy. It targets a significant improvement in sensitivity to cosmic gamma-rays and full-sky coverage capability by deploying two sophisticated arrays in the northern and southern hemispheres.

Core Objectives and Sensitivity Improvements

The CTA aims to achieve a factor of 5 to 10 improvement in sensitivity over current gamma-ray detection instruments, particularly focusing on the energy range between 100 GeV and 10 TeV. This enhancement is crucial for advancing the understanding of high-energy astrophysical phenomena, notably the mechanisms powering cosmic particle accelerators. The proposed design will enable CTA to extend gamma-ray observations to energies below 100 GeV and above 100 TeV.

Expected Scientific Impact

CTA is characterized by its potential to provide high-impact results in astrophysics, particle physics, and cosmology. Its scientific goals include unraveling the mysteries of cosmic ray origins, investigating black hole particle accelerators, and probing new physics like dark matter and quantum gravity effects. These inquiries are foundational to the broader astrophysical and particle physics communities as they strive to understand energetic processes in the universe.

Design and Technical Development

The CTA design leverages existing technologies and experience from its predecessors, such as H.E.S.S., MAGIC, and VERITAS. It consists of two arrays of varying telescope sizes to cover the wide energy range:

• Large Telescopes (LSTs): These capture low-energy gamma-rays and provide the focus for critical follow-up observations, particularly for transient events.
• Medium-Sized Telescopes (MSTs): These form the backbone of CTA, providing the necessary sensitivity in the core energy range.
• Small-Sized Telescopes (SSTs): These cater to the detection of the highest energy gamma-rays, covering large areas to maximize detection rates.

The novel approach in CTA's design includes using these diversely scaled arrays to optimize sensitivity across a range of energies, thus addressing the limitations of existing instruments and setting a new benchmark in high-energy astrophysical research tools.

Technical and Operational Innovations

Apart from improvements in sensitivity and energy range, CTA will introduce several key technical innovations:

• Open Observatory Model: For the first time in ground-based gamma-ray astronomy, the CTA will operate as an open observatory. It will allow broader access to the scientific community, enabling a more versatile and collaborative approach to gamma-ray astronomy.
• Data Management and Accessibility: The CTA will establish a Science Data Centre, offering access to preprocessed data and providing tools for analysis. These efforts will ensure transparency and enhance scientific output by involving a larger pool of astrophysicists.

Future Prospects and Collaborative Efforts

Emphasizing a worldwide collaborative effort, the CTA project extends far beyond European borders, with significant contributions from US, Brazilian, and Japanese groups. This international cooperation underscores the CTA's role as a global leader in very high energy gamma-ray astronomy.

In conclusion, the Cherenkov Telescope Array is poised to significantly transform gamma-ray astronomy by addressing existing observational barriers and introducing a broad scale of technical improvements. Its development will foster new discoveries and advance our understanding of the high-energy universe, making it an indispensable tool for researchers in astrophysics and related fields.