A Common Solution of Two Cosmic Puzzles
  The origin of the diffuse extragalactic gamma-ray background, which was measured with the large area telescope (LAT) aboard the Fermi satellite at energy below 820 GeV, and of the diffuse cosmic background of neutrinos, which was observed at much higher energies with the IceCube detector deep under the south pole ice, are among the current unsolved major cosmic puzzles. Here we show that their properties indicate a common origin: the decay of mesons produced in collisions of cosmic rays accelerated in relativistic jets with matter in/near source. Moreover, their properties are those expected if these highly relativistic jets are those that produce long duration gamma ray bursts in core collapse supernovae of type Ic, which take place mostly in the densest regions of giant molecular clouds in star forming galaxies, and those that are fired by blazars into their broad line region (BLR), which contains millions of mini-clouds. 
Shlomo Dado and Arnon Dar
astro-ph.HE