LHAASO protons versus LHAASO diffuse gamma-rays: a consistency check
arXiv:2506.06593 · doi:10.1093/mnrasl/slaf085
Abstract
We perform the first direct consistency check between the recently measured proton spectrum at the knee by Large High Altitude Air Shower Observatory (LHAASO) and the collaboration's own high-precision mapping of Galactic diffuse gamma-ray emission. By modeling the hadronic gamma-ray production using the updated cosmic-ray spectra, gas templates and cross-section models, we show that the predicted gamma-ray flux robustly overshoots the LHAASO data in both inner and lateral Galactic regions. This persistent mismatch in both normalization and spectral shape challenges conventional scenarios linking the local cosmic-ray sea to Galactic gamma-ray emission, and calls for a revision of current cosmic ray models in the TeV-PeV sky.
Accepted for publication in MNRAS Letters. Final version of the manuscript. 7 pages, 7 figures
References in corpus (10)
- HI4PI: A full-sky HI survey based on EBHIS and GASS
- Parametrization of gamma-ray production cross-sections for pp interactions in a broad proton energy range from the kinematic threshold to PeV energies
- Measurement of the cosmic-ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite
- Gamma-ray sky points to radial gradients in cosmic-ray transport
- Absorption of Very High Energy Gamma Rays in the Milky Way
- A signature of anisotropic cosmic-ray transport in the gamma-ray sky
- Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A
- Direct Measurement of the Cosmic-Ray Helium Spectrum from 40 GeV to 250 TeV with the Calorimetric Electron Telescope on the International Space Station
- Measurement of Very-high-energy Diffuse Gamma-ray Emissions from the Galactic Plane with LHAASO-WCDA
- Energy dependence of the knee in the cosmic ray spectrum across the Milky Way