Explosive events in the early universe

Abstract

Large-scale explosions, possibly the cumulative effects of supernovae, may have occurred in the early history of the Universe (z ranging between 2 and 10). The observed metal abundances in evolved stars in giant ellipticals suggest that as much as 10 to the 51-st power ergs per solar mass of metal-rich material might have been released. Alternatively, the energy output of any galaxy can be estimated at 5 times 10 to the 51-st power ergs per present visual solar luminosity. Blast waves from such a large input of energy could heat and ionize an intergalactic medium of closure density to a degree that would be consistent with the limits on both the 21-cm absorption in nearby radio sources and the L-alpha absorption in quasars. The bremsstrahlung radiation emitted by the ionized gas might explain the possible excess observed in the diffuse X-ray background below 1 keV.