Entering CTAO deployment: Commissioning and scientific verification of the first telescopes.

The Cherenkov Telescope Array Observatory (CTAO) will be the world’s leading gamma-ray observatory, covering energies from ~10 GeV to beyond 100 TeV. With up to ten times higher sensitivity, an extended energy range, and greatly improved angular resolution, CTAO will open new windows on the Universe’s most energetic processes.

CTAO is currently entering a decisive phase: At the northern site, four Large-Sized Telescopes (LSTs) are being commissioned, with a pathfinder Medium-Sized Telescope (MST) to follow. At the southern site, the first pathfinder MSTs and Small-Sized Telescopes (SSTs) are in production and scheduled for deployment in 2026. Mass production of additional telescopes is starting in parallel.

German university groups play a key role in these developments. Their contributions to construction, commissioning, and the technical and scientific validation of the telescopes are essential to CTAO’s success and secure Germany a strong position within the international consortium.

Seven universities and three non-university partners form the German CTAO network, working in four areas:

1. Contributions to LST: commissioning, software development, sustainable energy solutions.
2. Contributions to MST: construction, calibration and quality control of the FlashCam camera; development of mirror drives and alignment systems.
3. Contributions to SST: development of the SSTCam with TARGET electronics and SiPM technology.
4. Software and science Contributions : simulation tools and analysis frameworks.

Humboldt University is involved in one of these topics, ‘Contributions to MSTs,’ as part of the project ‘Contributions to the MST Telescope Structure’.