  Charm production gives rise to a flux of very high energy neutrinos from
astrophysical sources with jets driven by central engines, such as gamma ray
bursts or supernovae with jets. The neutrino flux from semi-leptonic decays of
charmed mesons is subject to much less hadronic and radiative cooling than the
conventional flux from pion and kaon decays and therefore has a dominant
contribution at higher energies, of relevance to future ultrahigh energy
neutrino experiments.
