Multi-Messenger Signatures of PeV-ZeV Cosmic Ray Sources

We discuss likely sources of cosmic rays in the $10^{15}-10^{20}$ eV range and their possible very high energy neutrino and gamma-ray signatures which could serve to identify these sources and constrain their physics. Among these sources we discuss in particular low luminosity gamma-ray bursts, including choked and shock-breakout objects, tidal disruption events and white dwarf mergers. Among efforts aimed at simultaneous secondary multi-messenger detections we discuss the AMON program.
Comment: 9 pages; Based on a talk given at the Origin of Cosmic Rays: Beyond the Standard Model 2016 conference in San Vito di Cadore, Dolomites; This is not a comprehensive review; it is weighted towards work the author has been more personally involved with. Fig 3 has been updated to reflect the published work