Orateur
Description
Recent observations have opened a new window on the long-standing question of the origin of Galactic cosmic rays up to PeV energies. In particular, the LHAASO experiment has revealed a population of ultra-high-energy gamma-ray sources extending beyond 100 TeV, providing compelling evidence for Galactic pevatrons (accelerating CRs up to 10$^{15}$ eV). These results challenge the traditional paradigm in which supernova remnants (SNRs) are the dominant sources of PeV cosmic rays, as most of the sources detected sources seem to not be associated with any SNR.
Additional candidates such as microquasars and X-ray binaries—where powerful jets and strong shocks can potentially accelerate particles to extreme energies—are gaining increasing attention alongside young massive stellar clusters, pulsar wind nebulae, and superbubbles. The latest observational breakthroughs will be reviewed, along with their implications and open questions on particle acceleration and escape.