The cosmic-ray sea explains the Galactic $\gamma$-ray and $\nu$ diffuse emissions from GeV to PeV

TL;DR

This paper demonstrates that the observed diffuse gamma-ray and neutrino emissions from the Galaxy from GeV to PeV energies can be explained by the cosmic-ray sea, aligning well with existing models based on cosmic-ray spectra measured by CALET, DAMPE, and KASCADE.

Contribution

It shows that the Galactic diffuse emissions observed by LHAASO are consistent with models assuming cosmic-ray spectra from existing measurements, without needing additional components.

Findings

LHAASO data agree with models based on cosmic-ray spectra from CALET, DAMPE, and KASCADE.

No extra components are required to explain the gamma-ray emissions from 1 TeV to 1 PeV.

Spatially dependent cosmic-ray transport models better fit the data than conventional models.

Abstract

The LHAASO collaboration has recently released the spectrum and the angular distribution of the gamma-ray Galactic diffuse emission from 1 TeV to 1 PeV measured with the Kilometer-2 Array (KM2A) and the Water Cherenkov Detector Array (WCDA). We show that those data are in remarkably good agreement with a set of pre-existing models that assume the emission to be produced by the Galactic population of cosmic rays if its spectral shape traces that measured by CALET, DAMPE as well as KASCADE at higher energies. No extra-components besides the CR sea is needed to explain LHAASO results. Spatial dependent CR transport models, although not required to reproduce LHAASO results, are in better agreement with them respect to conventional ones and needed to consistently reproduce Fermi-LAT and neutrino data.