 Interstellar sources of hydronium observations include the regions of Sagittarius B2, Orion OMC-1, Orion BN–IRc2, Orion KL, and the comet Hale–Bopp.Interstellar hydronium is formed by a chain of reactions started by the ionization of into by cosmic radiation.can produce either or through dissociative recombination reactions, which occur very quickly even at the low (≥10 K) temperatures of dense clouds.