High-energy cosmic neutrinos and photons from point sources, and implications for galactic confinement

The power input into highly relativistic electrons at the Crab pulsar nearly equals the neutron star's rate of energy loss due to spin-down. (a) Assuming that a newly formed pulsar is an 10% efficient accelerator of cosmic rays (approximately efficiency), and (b) adopting Ruderman's estimates of the initial pulsar spin-down rate (4 x 1043 ergs /sec), we calculate the rate at which neutrinos are detected. In 1011 tons of water, in 4 months, and for Esub(ν) >= 4 TeV, one can expect approximately 6 x 105 to 108 neutrino events from a supernova at 10 Kpc, and 1 to 300 from 7.5 Mpc; about 1 supernova per year occurs at the latter distance. These rates correspond to the range of estimated values of the original rate of spin-down. For the closed galaxy model of Peters and Westergaard, the required rate of energy input into cosmic rays is less by about two orders of magnitude. In the latter case, only galactic supernovae are likely to generate observable fluxes of neutrinos. Strong radio galaxies like Cen A are powerful emitters of gamma rays between 1011 and 1012 eV, and Cen A should yield approximately 10 neutrino events per year in a 1011 ton detector. (author)