  The observation of TeV-gamma rays of neutral pion origin from the supernova
remnant RX J1713.7-3946 might have revealed the first specific site where
protons are accelerated to energies typical of the main component of the cosmic
rays. In this letter we calculate the high-energy neutrino flux associated with
this source to be at least 40 muon-type neutrinos per kilometer-squared per
year. We perform the same calculations for other known sources of TeV-gamma
rays and show how neutrino observations can establish whether the TeV-gamma
rays emitted by blazars and supernova remnants are the decay products of
neutral pions and thus unequivocally establish the sources as cosmic
accelerators.
