The Institute of Astronomy, Geophysics and Atmospheric Sciences of the University of Sao Paulo (IAG/USP), the Italian National Institute for Astrophysics (INAF) and the North-West University of South Africa are partners in the construction of the ASTRI MINI-ARRAY of gamma-ray telescopes to observe the very high energy Universe, in the framework of the Cherenkov Telescope Array (CTA).
CTA is an international collaboration involving 30 countries, including Brazil, aiming at the construction of the largest Gamma-Ray Observatory until 2020. It will provide the deepest insight into the non-thermal high-energy Universe ever reached and allow significant contributions to Cosmology, Astrophysics, and Astroparticle Physics. It will probe the physical conditions of the cosmic ray accelerators, like black hole sources, pulsars, supernovae, and gamma-ray bursts; the composition and origin of the dark matter, and the cosmic magnetic fields. It will have a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and an extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the North, another in the Southern Hemisphere with about 100 telescopes of three different sizes) for full sky coverage and will be operated as an open observatory.
The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) MINI-ARRAY will be the PRECURSOR around which the CTA will later grow.
ASTRI will have 9 dual-mirror Cherenkov Telescopes of 4.3 m-diameter and will be installed in the CTA Southern site (in Namibia or in Chile) in near future.
The ASTRI PROTOTYPE was inaugurated in Serra la Nave, Catania, in September 2014 (supported by the Italian Ministry of Education, University and Research and the INAF). It has an innovative modular focal plane camera with silicon photo-multipliers and a logical pixel size of 6.2mm x 6.2mm.
ASTRI will extend and improve the sensitivity (which is similar to H.E.S.S. in the 1-10 TeV energy range) to about 100 TeV. It will allow for early technical assessment studies for the full CTA and the performance of competitive high energy science well before the deployment of the latter. In particular, it will allow the investigation of the poorly known cut-off regime of the cosmic ray accelerators and, by combining its good sensitivity with an angular resolution of a few arcmin and an energy resolution of about 10-15%, it will be well suited to study bright sources at very high energies (~10 TeV). An asset of the ASTRI MINI-ARRAY is its large field of view (9.6 degrees in diameter) which, combined with the good sensitivity up to a few degrees off-axis, will allow both to investigate extended sources and catch a few objects during the same pointing, maximizing the scientific return during the first months of operation.
IAG/USP will build 3 of the ASTRI MINI-ARRAY telescopes with support of FAPESP to the Thematic Project entitled: “Investigation of High Energy and Plasma Astrophysics Phenomena: Theory, Numerical Simulations, Observations, and Instrument Development for the Cherenkov Telescope Array (CTA)” coordinated by Elisabete M. de Gouveia Dal Pino (2013/10559-5). Brazilian engineers are currently participating in the testing and re-assessment of the prototype which will ensure full knowhow acquisition for future construction in Brazil of other telescopes for the CTA.
ASTRI MINI-ARRAY is one of the largest projects of the new Multi-Wavelength Astronomy Network of the Sao Paulo State mainly funded by FAPESP, whose mission is to make discoveries in Astronomy from the radio to the gamma-ray, via the development of novel and innovative technologies, the operation of world-class astronomy facilities, and the pursuit of fundamental astronomical research.