High energy neutrino yields from astrophysical sources

2006

We calculate the yield and flavour content of high energy neutrinos produced in astrophysical sources with negligible magnetic fields varying their interaction depth. We take into account the scattering of secondaries on background photons as well as the direct production of neutrinos in decays of charm mesons. If multiple scattering of nucleons becomes important, the neutrino spectra from meson and muon decays are strongly modified with respect to transparent sources. Characteristic for neutrino sources containing photons as scattering targets is a strong energy-dependence of the ratio R0 of νμ and νe fluxes at the sources, ranging from R0=μ/e~0 below threshold to R0~4 close to the energy …