Orateur
Description
Gamma-ray observations provide important information on cosmic-ray (CR) propagation in our Galaxy.
First, we present a new model of CR propagation in the Milky Way, where CRs are injected at discrete transient sources in the disc. We then calculate the corresponding diffuse Galactic gamma-ray emission. We find that the diffuse gamma-ray emission at >~ 100 TeV is very clumpy, and does not correlate with the gas density along the line of sight. It is substantially different from the relatively smoother emission detected by Fermi at ~ GeV energies. We also discuss how many hadronic and leptonic PeVatrons would be detectable in our simulations, and compare with LHAASO data. We show that this allows to place new constraints on PeV CR sources.
Second, we discuss TeV gamma-ray halos around old pulsars. We show that current gamma-ray measurements place interesting constraints on the turbulent magnetic fields around these pulsars, and we examine the implications for CR transport. In particular, we study the case of LHAASO’s “peanut-shaped” source.
Finally, we discuss the implications of the observed TeV-PeV cosmic-ray anisotropies on CR propagation in the ISM.