Obtaining this international legal framework will enable engineers and researchers from the 11 member countries and ESO to move ahead rapidly with the construction and commissioning of CTAO, one of the most ambitious ground-based telescope array projects of the 21st century.
Dedicated to the study of gamma rays in the Universe, CTAO consists of two telescope arrays currently being deployed in the northern and southern hemispheres one in Spain, the other in Chile.
Eventually, CTA will comprise a total of 118 telescopes, designed in three different sizes : small, medium and large.
While the first of the large telescopes (LST-1.23 m) is in the commissioning phase at La Palma and is already delivering impressive scientific results ( https://www.ctao.org/news/lst-1-discovers-the-most-distant-agn-at-very-high-energies/ ), operations with intermediate arrays are expected to start in 2026.
Observatoire de Paris - PSL’s contributions to CTAO
25 countries contribute to CTAO, with over 150 institutes worldwide. Among them, Observatoire de Paris - PSL is a member of the consortium.
Teams from the Laboratoire d’étude de l’Univers et des phénomènes eXtrèmes - LUX and the UNité d’Ingénierie et de Développements Instrumentaux pour l’Astrophysique - UNIDIA are heavily involved at several levels :
in the preparation of high-level data archiving and distribution,
in the development of analysis software,
and in the design and construction of small telescopes (SST, 4m).
Since 2015, Observatoire de Paris - PSL has been home to the French prototype of a small “Schwarzschild-Couder” telescope (SST), which it developed on the basis of a pioneering technological concept.
A tender has just been launched for the manufacture of 12 electro-mechanical structures for the SSTs. The first SSTs will be installed on the Chile site in early 2026.
The CTAO team at Paris Observatory - PSL
At LUX : O. Ates, C. Boisson, P. Cristofari, C. Galelli, J.-M. Martin, M. Servillat, H. Sol, S. Vergani, A. Zech ;
At UNIDIA : J.-L. Dournaux, J-P Amans, J. Cailleux, F. De Frondat, P. Laporte.
CTAO’s unrivalled sensitivity and energy coverage ( 20 GeV - 300 TeV) will pave the way for major advances in LUX research into blazars and other active galactic nuclei, gamma-ray bursts (GRBs) and cosmic-ray acceleration in “PeVatrons”.
