The LHAASO PeVatron Bright Sky: What We Learned

Abstract

The recent detection of 12 γ-ray galactic sources well above E>100 TeV by the LHAASO observatory has been a breakthrough in the context of the search for the origin of cosmic rays (CR). Although most of these sources remain unidentified, they are often spatially correlated with leptonic accelerators, such as pulsar and pulsar wind nebulae (PWNe). This dramatically affects the paradigm for which a γ-ray detection at E>100 TeV implies the presence of a hadronic accelerator of PeV particles (PeVatron). Moreover, the LHAASO results support the idea that sources other than the standard candidates, supernova remnants, can accelerate galactic CRs. In this context, the good angular resolution of future Cherenkov telescopes, such as the ASTRI Mini-Array and CTA, and the higher sensitivity of future neutrino detectors, such as KM3NeT and IceCube-Gen2, will be of crucial importance. In this brief review, we want to summarize the efforts made up to now, from both theoretical and experimental points of view, to fully understand the LHAASO results in the context of the CR acceleration issue.