The Milky Way at PeV Energies
by
seminar room 3
bldg. 1b
The physical origin of the knee, a break in the cosmic ray (CR) spectrum at the energy 4 PeV, is more than 60 years after its discovery still unclear. Similarly, the search for PeVatrons, i.e. Galactic sources able to accelerate CR protons up to PeV energies, has been for a long time unsuccessful. However, the increased sensitivity of current experiments, in particular LHAASO, has the potential to improve the measurements in this energy range considerably. After a brief review of Galactic CR propagation, I discuss observations of the "diffuse" Galactic photon flux, possible interpretations and the connection to CRs and neutrinos. In the final part of the talk, I will argue that the high-mass X-ray binary Cygnus X-3 can be a PeVatron and discuss observable signatures of different acceleration mechanisms.