Neutrino Constrains to the Diffuse Gamma-Ray Emission from Accretion Shocks

摘要: Accretion of gas during the large scale structure formation has been thought to give rise shocks that can accelerate cosmic rays. This process then results in an isotropic extragalactic gamma-ray emission contributing background observed by Fermi-LAT. Unfortunately this difficult constrain and thus presents uncertain foreground any attempts extract potential dark matter signal. Recently, IceCube detected high-energy neutrino flux which could be origin. In general, neutrinos linked gamma rays since cosmic-ray interactions produce neutral charged pions where decay into rays, while neutrinos. By assuming are entirely produced accelerated accretion formation, we obtain strongest constraint from (strong) find they make at best ~20% background, corresponding with spectral index 2, or ~10% for 2.46. Since typical objects galaxy clusters, fluxes used determine a dominant cluster type acceleration efficiency, probe formation.