Description
Clarifying origins and acceleration mechanisms of the most energetic particles in the universe has been a decades-long endeavor, being one of the most intriguing mysteries in the interdisciplinary research among astroparticle physics, high-energy physics and nuclear physics. Since such ultra-high-energy cosmic rays (UHECRs) are deflected less strongly by the galactic and inter-galactic magnetic fields, due to their enormous kinetic energies, their arrival directions are ostensively correlated with their origins. A next-generation astronomy using UHECRs is hence a potentially viable probe to unravel mysteries of extremely energetic phenomena in the nearby universe. In this talk, I will highlight the introductory cosmic-ray physics, detection techniques and latest results of the two giant observatories, dubbed Telescope Array experiment and Pierre Auger Observatory including their on-going upgrades and address scientific objectives and requirements for future UHECR observatories.
