1) Short drama 
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. Currently under design is the Cherenkov Telescope Array (CTA). == Background == Due to th...