Compute neutrino spectra from PionDecay radiative model?

[lmohrmann]

The Kelner et al. 2006 paper (https://ui.adsabs.harvard.edu/abs/2006PhRvD..74c4018K/abstract) also provides parametrizations for neutrino spectra. Unfortunately, it seems that the Kafexhiu et al. (2014) paper (https://ui.adsabs.harvard.edu/abs/2014PhRvD..90l3014K/abstract) does not.

@zblz Have you ever considered implementing the prediction of neutrino spectra from the PionDecay model? Would you see this as a useful addition to naima? Could it be done using the parametrizations in the Kelner paper?