  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.
