CTA, the Cherenkov Telescope Array, is going to be the next milestone in ground-based gamma-ray astronomy. CTA stands for an initiative to build the next generation ground-based gamma-ray instrument, which is intended to serve as an open observatory to a wide astrophysics community and which will provide the deepest ever insight into the non-thermal high-energy universe. It foresees a factor of 5-10 improvement in sensitivity in the current energy domain of about 100 GeV to some 10 TeV and an extension of the accessible energy range well below 100 GeV and to above 100 TeV. The observatory will consist of two arrays: a southern hemisphere array, which covers the full energy range from some 10 GeV to about 100 TeV to allow for a deep investigation of galactic sources, and of the central part of our Galaxy, but also for the observation of extragalactic objects. A northern hemisphere array, consisting of the low energy instrumentation (from some 10 GeV to ~1 TeV) complements the observatory and is dedicated mainly to northern extragalactic objects. The observatory with its two sites will be operated by one single consortium. A significant fraction of the observation time will be open to the general astrophysical community and facilities for user support will be provided. The design of CTA is based on currently available technology, and therefore allows for reliable predictions of the performance parameters of the observatory.
Building on the expertise gained in the HESS experiment, the APC is a major partner in the CTA collaboration. The François Arago Centre is used in order to help with the preparation of the project, e.g. in designing the prototype of the proposal handling platform and providing resources for Monte-Carlo simulations. For the operational phase, the François Arago Centre will play a major role in data analysis and data centre activities.