Speaker
Description
Recently, the LHAASO Collaboration has released the highest-energy measurements of the diffusive gamma-ray flux, offering the opportunity to study the spatial distribution and energy spectrum of Galactic cosmic rays (CRs) in the TeV-PeV sky through a multi-messenger approach. In addition, high-precision observations of the CR proton, helium and all-particle fluxes across the spectral feature known as the 'knee' ($\sim$ few PeV) have also been announced by the same collaboration. However, a persistent tension between the two observed components seems to be challenging conventional scenarios linking the local CR sea to the Galactic gamma-ray emission. In the present work, we explore as a possible alternative the scenario of a dominating contribution of a local PeVatron to the CR 'knee'. We developed an analytical-phenomenological hybrid model of the galactic CR flux using the latest data available by satellite missions and ground-based observatories, including the uncertainty related to the contribution of heavier nuclei in the CR composition. We compare the diffuse gamma-ray flux from our model with recent observational data and discuss the conditions of the CR populations that may alleviate the aforementioned tension, within the uncertainties of the Galactic gas distribution.