New limit on high Galactic latitude PeV gamma-ray flux from Tibet AS-gamma data

Abstract

Tibet AS-gamma collaboration has recently reported detection of gamma-rays with energies up to Peta-electronvolt from parts of the Galactic plane. We notice that the analysis of gamma-ray flux by the Tibet AS-gamma experiment also implies an upper bound on the diffuse gamma-ray flux from high Galactic latitudes(|b|>20 degrees) in the energy range between 100 TeV and 1 PeV. This bound is up to an order-of-magnitude stronger than previously derived bounds from GRAPES3, KASCADE and CASA-MIA experiments. We discuss the new TibetAS-gamma limit on high Galactic latitude gamma-ray flux in the context of possible mechanisms of multi-messenger (gamma-ray and neutrino) emission from nearby cosmic ray sources, dark matter decays and large scale cosmic ray halo of the Milky Way.

4 pages, 3 figures, accepted to A&A

References in corpus (12)

• Direct detection of a break in the teraelectronvolt cosmic-ray spectrum of electrons and positrons
• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• Observation and Characterization of a Cosmic Muon Neutrino Flux from the Northern Hemisphere using six years of IceCube data
• The IceCube high-energy starting event sample: Description and flux characterization with 7.5 years of data
• The contribution of Fermi-2LAC blazars to the diffuse TeV-PeV neutrino flux
• First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies
• A Galactic Halo Origin of the Neutrinos Detected by IceCube
• Directional association of TeV to PeV astrophysical neutrinos with radio blazars
• Escape of cosmic rays from the Galaxy and effects on the circumgalactic medium
• Pion decay model of TIBET-AS$\gamma$ PeV gamma-ray signal
• Fluxes of diffuse gamma rays and neutrinos from cosmic-ray interactions with circumgalactic gas
• Multi-messenger Implications of Sub-PeV Diffuse Galactic Gamma-Ray Emission