Fireballs from Superconducting Cosmic Strings
  Thermalized fireballs should be created by cusp events on superconducting cosmic strings. This simple notion allows to reliably estimate particle emission from the cusps in a given background magnetic field. With plausible assumptions about intergalactic magnetic fields, the cusp events can produce observable fluxes of high-energy photons and neutrinos with unique signatures. 
Andrei Gruzinov and Alexander Vilenkin
astro-ph.HE hep-th