We report on a compelling similarity of the energy and radial distributions of multi-TeV CRs extracted from observations of gamma-rays and gas distributions near three young star clusters. The derived 1/r decrement of the CR density with the distance from a star cluster is a distinct signature of continuous, over a few million years, CR injection into the interstellar medium. The hard spectra and high acceleration efficiency reveal that these your star clusters are promising PeVatron candidate and may dominate the flux of highest energy galactic CRs.

What is the purpose of dust in our Universe? Experts in astronomy discuss how dust is a key ingredient to the formation of our Solar System, the development of life and even in understanding a galaxy.