Unveiling the transport of Galactic cosmic rays with diffuse γ-rays and neutrinos at the highest energies

The Tibet-ASγ and LHAASO collaborations recently provided the first evidence of diffuse γ-ray emission from the Galactic plane up to the PeV range. Due to the challenges this poses to current theoretical models, it is crucial to carefully study different scenarios of diffuse γ-ray production, specially towards the centre of the Galaxy. Moreover, IceCube achieved the first measurements of the neutrino emission from the Galactic plane, offering a complementary tool to study the distribution of Galactic cosmic rays up to the knee. Remarkably, these observations provide a unique tool to study the origin of the most energetic Galactic cosmic rays, the propagation of these particles in different regions of the Galaxy and their composition.

In this talk, I’ll discuss how measurements of the gamma-ray and neutrino diffuse emissions are correlated to the production and transport of cosmic rays in the Galaxy and what the implications of these recent observations are in our theoretical models. In particular, I’ll show that current observations are compatible with the expected emission from diffuse cosmic rays, with unresolved sources playing a subdominant role, and the first hints that seem to favor scenarios of non-uniform propagation of cosmic rays in the Galaxy.

Fecha: 10/09/2025 – 12:30
Pedro de la Torre Luque
Instituto de Física Teórica UAM-CSIC