The 2nd LHAASO Symposium

Cosmic ray (CR) hadrons with GeV-PeV energies are expected to reside in the circumgalactic medium (CGM) around the Milky Way (MW), having escaped from the Galactic disk, or injected in situ by satellite galaxies, large scale shocks due to Galactic winds, etc. In some cases, circumgalactic CRs (CGCRs) may play important thermal and dynamical roles in the evolution of galaxies, but observational...

The origin of cosmic rays (CRs) remains an open question. The CR spectrum is characterized by two main breaks: the knee at ~3 PeV (1e15 eV) and the ankle at ~3 EeV (1e18 eV). It is widely accepted that ultra-high-energy cosmic rays (UHECRs) above the ankle originate from extragalactic sources, with the transition energy between galactic and extragalactic components lying between the knee and...