Observations of the high energy particle accelerators in our Universe

Nahee Park (Queen’s University)

November 20, 2023

–

Abstract: We have known of the existence of high-energy particles in our Universe based on observations of cosmic rays up to 10^21 eV. With energies more than ten orders of magnitude higher than solar energetic particles, these cosmic rays should be accelerated under more extreme environments than our Sun can provide. Such environments include supernova remnants, active galactic nuclei, and gamma-ray bursts. However, since cosmic rays are deflected by magnetic fields, observations of gamma rays and neutrinos produced by cosmic-ray interactions of have been expected to provide key measurements necessary to locate the source sites where cosmic rays are accelerated. In recent decades, we have seen great improvements in gamma-ray and neutrino measurements. High-energy gamma-ray observations have revealed over 200 astrophysical objects emitting gamma rays with energies higher than 100 GeV. Complementing this, we have begun to see hints of neutrino sources above tens of TeV. I will present an overview of current high-energy gamma-ray and neutrino observations of high-energy particle accelerators in our Universe and a glimpse into what the future holds.