Problem with pion decay

[llsico]

I'm studying naima, and I'm trying to use it to reproduce the SED that we have in the Linden 2012 paper . The idea here is not very complex, I took the density given in this paper (Fig 01) and passed it on to naima, specifically for the radiative mode of pion decay. As I have the density for different distances, I calculated the pion decay for each one of them and in the end I added it all up, but the curve I get is very different from the one in Fig. 02 of the paper. Does anyone have any idea why?