The LHAASO PeVatron bright sky: what we learned

TL;DR

The paper reviews recent LHAASO gamma-ray detections above 100 TeV, discussing their implications for cosmic ray origins, the nature of gamma-ray sources, and the importance of future observational tools.

Contribution

It provides a comprehensive summary of current theoretical and experimental efforts to interpret LHAASO results in the context of cosmic ray acceleration.

Findings

LHAASO detected 12 gamma-ray sources above 100 TeV.

Many sources are associated with leptonic accelerators, challenging previous assumptions.

Future telescopes and neutrino detectors will be crucial for further understanding.

Abstract

The recent detection of 12 gamma-ray Galactic sources well above E > 100 TeV by the LHAASO observatory has been a breakthrough in the context of Cosmic Ray (CR) origin search. Although most of these sources are unidentified, they are often spatially correlated with leptonic accelerators, like pulsar and pulsar wind nebulae (PWNe). This dramatically affects the paradigm for which a gamma-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 done 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.