The high-energy galactic tau neutrino flux and its atmospheric background

We compare the tau neutrino flux arising from the galaxy and the earth atmosphere for $10^{3} \leq E/\mbox{GeV} \leq 10^{11}$. The intrinsic and oscillated tau neutrino fluxes from both sources are considered. We find that, for E≥ 103 GeV, the oscillated ντ flux along the galactic plane dominates over the maximal intrinsic atmospheric ντ flux, i.e., the flux along the horizontal direction. We also briefly comment on the prospects for observing these high-energy tau neutrinos. PACS: 95.85.Ry Neutrino, muon, pion, and other elementary particles; cosmic rays – 13.85.Tp Cosmic-ray interactions