Astrophysical neutrino event rates and sensitivity for neutrino telescopes

Spectacular processes in astrophysical sites produce high-energy cosmic rays, which are further accelerated by Fermi shocks into a power-law spectrum. These, in passing through radiation fields and matter, produce neutrinos. Neutrino telescopes are designed with large detection volumes to observe such astrophysical sources. A large volume is necessary because the fluxes and cross sections are small. We estimate various telescopes' sensitivities and expected event rates from astrophysical sources of high-energy neutrinos. We find that an ideal detector with a km² incident area can be sensitive to a flux of neutrinos integrated over energy from 10⁵ and 10⁷ GeV as low as 1.3 × 10^-8E^-2 (GeV cm^-2 s^-1 sr^-1), which is 3 times smaller than the Waxman-Bahcall conservative upper limit on potential neutrino flux. A real detector will have degraded performance. Detection from known point sources is possible but unlikely unless there is prior knowledge of the source location and neutrino arrival time.