Cosmic ray composition measurements and cosmic ray background free gamma-ray observations with Cherenkov telescopes

Understand

Muon component of extensive air showers (EAS) initiated by cosmic ray particles carries information on the primary particle identity.

• We show that the muon content of EAS could be measured in a broad energy range from 10-100 TeV up to ultra-high-energy cosmic ray range using wide field-of-view imaging atmospheric Cherenkov telescopes observing strongly inclined or nearly horizontal EAS from the ground of from high altitude.
• Cherenkov emission from muons in such EAS forms a distinct component (halo or tail) of the EAS image in the telescope camera.
• We show that detection of the muon signal could be used to measure composition of the cosmic ray spectrum in the energy ranges of the knee, the ankle and of the Galactic-to-extragalactic transition.