Fig. 2: Derived ratio of the average luminosity of an external, Milky Way-like Galaxy and the Galactic luminosity in gigaelectronvolt–teraelectronvolt γ-rays and teraelectronvolt–petaelectronvolt neutrinos.
From: The Milky Way revealed to be a neutrino desert by the IceCube Galactic plane observation
γ-rays are shown in red; neutrinos are shown in blue. The ratio is calculated using equations (1), (2), (4) and (5) with the Fermi-LAT and IceCube measurements of the GDE. The dark-shaded regions adopt the benchmark extragalactic model parameters and assume a uniform emissivity within the Galactic disk. Their widths correspond to the uncertainties in the GDE and EB observations. The dashed curves use not only the benchmark extragalactic model but also a more realistic Galactic model that takes into account the spatial distribution of sources and gas in the Milky Way. The light-shaded region further accounts for the uncertainties in the parameters of the extragalactic model.
