http://arxiv.org/abs/2305.06948
The diffuse gamma-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured precisely by the Large High Altitude Air Shower Observatory (LHAASO), which is very useful in constraining the propagation and interaction of cosmic rays in the Milky Way. On the other hand, new measurements of CR spectra reach a very high precision up to 100 TeV energies, revealing multiple spectral structures of various species. In this work, we confront the model prediction of the diffuse gamma-ray emission, based on up-to-date measurements of the local cosmic ray spectra and simplified propagation setup, with the measurements of diffuse gamma-rays. To better constrain the low-energy part of the model, we analyze Fermi-LAT data to extract the diffuse emission between 1 and 500 GeV from the same sky regions of LHAASO. Compared with the prediction, we find that clear excesses between several GeV and ~60 TeV of the diffuse emission exist. Possible reasons to explain the excesses may include unresolved sources or more complicated propagation models. We illustrate that an exponential-cutoff-power-law component with an index of -2.40 and cutoff energy of ~30 TeV is able to account for such excesses.
R. Zhang, X. Huang, Z. Xu, et. al.
Fri, 12 May 23
7/53
Comments: N/A