Abstract

Invited Talk - Splinter SKA   (MW-1050)

Probing the High-Energy Universe with Cosmic Rays through SKA-Low

Keito Watanabe for the SKA HECP SWG
Institute for Astroparticle Physics, Karlsruhe Institute of Technology

The origins of cosmic rays above 10$^{15}$ eV have been unresolved to this day, ever since their initial discovery. At these high energies, cosmic rays are indirectly observed at Earth through the secondary products generated by extensive air showers, a cascade of particles initiated by interactions of cosmic rays within the atmosphere. The electromagnetic particles in the shower also induce radio waves in the MHz frequency regime, which can be directly observed through an array of radio antennas. With measurements from LOFAR, we have already reconstructed key observables of cosmic rays, such as the atmospheric depth at the shower maximum, the arrival direction, and the energy of the particle -- with high precision, competitive to particle-based detectors. With its extremely densely populated core and much broader bandwidth than LOFAR, SKA-Low will allow us to reconstruct observables with an unprecedented accuracy even higher than that of LOFAR, and unlike any other existing or planned detector. With novel reconstruction methods actively being developed for the SKA-Low, we will also open the window that enables us to reconstruct the entire air-shower development, probe within the air shower to understand the high-energy hadronic interactions with anomalous air showers, and potentially measure PeV gamma-rays with efficient photon/hadron separation. With a dedicated radio-quiet particle detector array as trigger for readout of the voltage buffers, cosmic ray measurements will be performed fully commensally alongside regular observations of SKA-Low. In this talk, I will showcase the current status of the observational strategies for the measurement of high-energy cosmic rays with SKA-Low, and its potential applications to further enhance our understanding of the high-energy universe.