Testing hadronic and photohadronic interactions as responsible for ultrahigh energy cosmic rays and neutrino fluxes from starburst galaxies

We test the hypothesis of starburst galaxies as sources of ultra-high energy cosmic rays and high- energy neutrinos. The computation of interactions of ultra-high energy cosmic rays in the starburst environment as well as in the propagation to the Earth is made using a modified version of the Monte Carlo code SimProp, where hadronic processes in the environment of sources are implemented for the first time. Taking into account a star-formation-rate distribution of sources, the fluxes of ultra-high energy cosmic rays and high-energy neutrinos are computed and compared with observations, and the explored parameter space for the source characteristics is discussed. We find that, depending on the density of the gas in the source environment, spallation reactions could exceed the outcome in neutrinos from photo-hadronic interactions in the source environment and in the extra-galactic space.