Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layout

International audienceThe Cherenkov Telescope Array (CTA) is the major next-generation observatory for ground-based very-high-energy gamma-ray astronomy. It will improve the sensitivity of current ground-based instruments by a factor of five to twenty, depending on the energy, greatly improving both their angular and energy resolutions over four decades in energy (from 20 GeV to 300 TeV). This achievement will be possible by using tens of imaging Cherenkov telescopes of three successive sizes. They will be arranged into two arrays, one per hemisphere, located on the La Palma island (Spain) and in Paranal (Chile). We present here the optimised and final telescope arrays for both CTA sites, as well as their foreseen performance, resulting from the analysis of three different large-scale Monte Carlo productions

Science with the Cherenkov Telescope Array

The Cherenkov Telescope Array, CTA, will be the major global observatory forvery high energy gamma-ray astronomy over the next decade and beyond. Thescientific potential of CTA is extremely broad: from understanding the role ofrelativistic cosmic particles to the search for dark matter. CTA is an explorerof the extreme universe, probing environments from the immediate neighbourhoodof black holes to cosmic voids on the largest scales. Covering a huge range inphoton energy from 20 GeV to 300 TeV, CTA will improve on all aspects ofperformance with respect to current instruments. The observatory will operate arrays on sites in both hemispheres to providefull sky coverage and will hence maximize the potential for the rarestphenomena such as very nearby supernovae, gamma-ray bursts or gravitationalwave transients. With 99 telescopes on the southern site and 19 telescopes onthe northern site, flexible operation will be possible, with sub-arraysavailable for specific tasks. CTA will have important synergies with many ofthe new generation of major astronomical and astroparticle observatories.Multi-wavelength and multi-messenger approaches combining CTA data with thosefrom other instruments will lead to a deeper understanding of the broad-bandnon-thermal properties of target sources. The CTA Observatory will be operated as an open, proposal-driven observatory,with all data available on a public archive after a pre-defined proprietaryperiod. Scientists from institutions worldwide have combined together to formthe CTA Consortium. This Consortium has prepared a proposal for a CoreProgramme of highly motivated observations. The programme, encompassingapproximately 40% of the available observing time over the first ten years ofCTA operation, is made up of individual Key Science Projects (KSPs), which arepresented in this document