IISER MOHALI

Abstract: Every second, hundreds of high-energy particles from outer space, known as cosmic rays, pass through every square metre of Earth's surface. Their origin remains one of the greatest unsolved mysteries in astrophysics even after a century of their discovery. The GRAPES-3 Observatory at Ooty, India, one of the world's major facilities for cosmic ray research, has been designed and built with the objective to unravel this mystery. In this talk after introducing to cosmic ray research, I will then present the GRAPES-3 experiment and highlight some of its recent scientific achievements, including the discovery of a new spectral feature in the cosmic-ray proton spectrum around 165 TeV and precision measurements of cosmic-ray anisotropies. Finally, I will discuss the ongoing upgrades to the observatory, which aim to significantly enhance its sensitivity to PeV gamma rays, opening a new window for exploring the most powerful particle accelerators in the Universe.