PIONIC PHOTONS AND NEUTRINOS FROM COSMIC RAY ACCELERATORS

Identifying the accelerators that produce the Galactic and extragalactic cosmic rays has been a priority mission of several generations of high energy gamma ray and neutrino telescopes; success has been elusive so far. Detecting the gamma ray and neutrino fluxes associated with cosmic rays reaches a new watershed with the completion of Ice Cube, the first neutrino detector with sensitivity to the anticipated fluxes, and the construction of CTA, a ground-based gamma-ray detector that will map and study candidate sources with unprecedented precision. In this paper, we revisit the prospects for revealing the sources of the cosmic rays by a multiwavelength approach; after reviewing the methods, we discuss supernova remnants, gamma-ray bursts, active galaxies and GZK neutrinos in some detail.