emission from that originating from dark matter annihilation using spatial considerations (sec. \[sec:space\]). Thirdly, the spectral analysis (sec \[sec:specs\]) will in general be affected, depending on the spectrum of the emission, and a broken power law feature could arise at low Fermi energies where the emission from primary electrons may become comparable to that from primary hadronic cosmic rays. Finally, it is possible that clusters that host a bright active nucleus and, concurrently, exhibit significant IC emission from an accretion shock would feature a [*double peak*]{} in the spatial distribution of high-energy cosmic-ray sources. Such a circumstance cannot be described by the radial power-law functional form we adopt in the simplified spatial model for the distribution of cosmic-rays described below.

Bearing the above caveats in mind, for simplicity we assume here that the dominant source for the gamma-ray emission from galaxy clusters at energies relevant to Fermi originates from inelastic collisions of hadronic cosmic rays [@Reimer:2004ac; @Berezinsky:1996wx]. Following the arguments outlined above, we then follow the analytical cosmic-ray model outlined in [@pfrommer2004; @pfrommer2007; @nagaiando]. In this scenario, the primary proton injection spectrum is described by a simple power law, parametrized by a spectral index $\alpha_p$ independent of the position in 