Microquasars as the major contributors to Galactic cosmic rays around the "knee"

Recently, LHAASO detected a gamma-ray emission extending beyond 100\,TeV from 4 sources associated to powerful microquasars. We propose that such sources are the main Galactic PeVatrons and investigate their contribution to the proton and gamma-ray fluxes by modeling their entire population. We find that the presence of only ~10 active powerful microquasars in the Galaxy at any given time is sufficient to account for the proton flux around the knee and to provide a very good explanation of cosmic-ray and gamma-ray data in a self-consistent picture. The 10\,TeV bump and the 300\,TeV hardening in the cosmic-ray spectrum naturally appear, and the diffuse background measured by LHAASO above a few tens of TeV is accounted for. This supports the paradigm in which cosmic rays around the knee are predominantly accelerated in a very limited number of powerful microquasars.