SPECTRAL FEATURES FROM THE REIONIZATION EPOCH

Emission lines in hydrogen can be used to measure the approximate reds hift of the reionization of the universe. This is an important measure ment given the lack of a convincing theoretical prediction of this epo ch. There is a rapid change in absorption at the reionization event, w hich can leave sharp features in the spectrum of recombining hydrogen. These features in the near-infrared background permit us to measure t he redshift at which reionization occurs. We have calculated these sig nals based on numerical simulations of the ACDM cosmogony.