rays produced in neutral pion decays resulting fomr the above mentioned inelastic cosmic-ray proton collisions [@Berrington:2002bh]. The energy stored in the secondary electron-positron pairs is predicted to contribute at the level of 1% or less of the total power associated to the primary cosmic ray protons [@Berrington:2002bh]. In terms of the gamma-ray emission, ref. [@nagaiando] estimates that only for very low average cluster magnetic fields and for very steep proton injection spectral indexes can the secondary inverse Compton contribution be even 10% of that from $\pi^0$ decay.

Although secondary $e^\pm$ inverse Compton emission is likely subdominant compared to neutral pion decay gamma-ray yields, during the early stages of a merger, [*primary*]{} electrons can still make a significant contribution to the GeV radiation. The gamma-ray emission is, again, dominantly associated to the inverse Compton of, here, primary cosmic-ray electrons off of the microwave radiation background. The resulting inverse Compton flux is suppressed compared to the hadronic gamma-ray production from nuclear interactions involving non-thermal protons only as long as the efficiency of acceleration of hadronic species exceeds that for electrons [@Keshet:2002sw]. While this is indeed the expectation in diffusive shock acceleration theory [@Berrington:2002bh], the reader should bear in mind that the model 