What is "iact"

IACT stands for Imaging Atmospheric (or Air) Cherenkov Telescope or Technique. It is a device or method to detect very high energy gamma-ray photons in the 50 GeV to 50 TeV range. There are currently three operating IACT systems: H.E.S.S., MAGIC, and VERITAS. Set to be the world's largest telescope at the highest altitude, the Major Atmospheric Cerenkov Experiment Telescope (MACE) is currently being established at Hanle, Ladakh, India. Also, currently under design is the Cherenkov Telescope Array (CTA).