Left: likelihood scan of the cosmic-ray density profile parameter space for E_CR ≳ 10 TeV, for a centrally peaked profile of the form ρ_CR ∝ 1/r^α, based on the MAGIC measurements. The scan has been performed for two different model assumptions: (1) only the cosmic-ray population with the power-law distribution exists (solid lines) and (2) the power-law population exist on top of a uniform cosmic-ray density distribution (dashed lines). Magenta crosses mark the best fit values for both assumptions, which nearly exactly overlap for our data. Gray vertical dash-dotted line represents the mean cosmic-ray density from H.E.S.S. Collaboration (2016). The mean cosmic-ray energy density ⟨w_CR⟩ estimated here corresponds to the Galactic longitude range [ − 1° ;1° ]. Right: marginalization of the scan over the cosmic-ray profile index only. Green boxes and blue error bars mark the 1 and 2σ confidence ranges correspondingly for assumptions 1 (dark colours) and 2 (light colours).