Pinpointing the knee of cosmic rays with diffuse PeV gamma-rays and neutrinos

Abstract

The origin of the knee in cosmic ray spectrum remains to be an unsolved fundamental problem. There are various kinds of models which predict different break positions and the compositions of the knee. In this work, we suggest to use diffuse $\gamma$-rays and neutrinos as probes to test these models. Based on several typical types of the composition models, the diffuse $\gamma$-ray and neutrino spectra are calculated, which show distinctive cutoff behaviours at energies from tens of TeV to multi-PeV. The expected flux will be observable by the newly upgraded Tibet-AS$\gamma$+MD (muon detector) experiment as well as more sensitive future projects, such as LHAASO and HiSCORE. By comparing the neutrino spectrum with the recent observations by IceCube experiment, we find that the diffuse neutrinos from interactions between the cosmic rays and the interstellar medium may not be responsible to the majority of the IceCube events. Future measurements of the neutrinos may be able to identify the Galactic diffuse component and further shed light on the problem of the knee of cosmic rays.

Accepted for publication in the ApJ; 6 figures

References in corpus (6)

• Evidence for High-Energy Extraterrestrial Neutrinos at the IceCube Detector
• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Probing the Galactic Origin of the IceCube Excess with Gamma-Rays
• Cosmic Neutrino Pevatrons: A Brand New Pathway to Astronomy, Astrophysics, and Particle Physics
• On the e${}^{+}$e${}^{-}$ excesses and the knee of the cosmic ray spectra -- hints of cosmic rays acceleration at young supernova remnants
• Search for Galactic PeV Gamma Rays with the IceCube Neutrino Observatory

Cited by in corpus (7)

• A Combined Astrophysical and Dark Matter Interpretation of the IceCube HESE and Throughgoing Muon Events
• On the IceCube spectral anomaly
• Constraints to a Galactic Component of the Ice Cube cosmic neutrino flux from ANTARES
• Implications of Fermi-LAT observations on the origin of IceCube neutrinos
• On the Contribution of "Fresh" Cosmic Rays to the Excesses of Secondary Particles
• The Galactic Center: A PeV Cosmic Ray Acceleration Factory
• Spatial and temporal structure of EAS reflected Cherenkov light signal