NEUTRAL HYDROGEN AT HIGH REDSHIFTS AS A PROBE OF STRUCTURE FORMATION .3. RADIO MAPS FROM N-BODY SIMULATIONS

Large inhomogeneities in neutral hydrogen in the Universe can be detec ted at redshifts z less than or equal to 10 using the redshifted 21-cm line emission. We use cosmological N-body simulations for dark matter and a simple model for baryonic collapse to estimate the signal expec ted from structures like protoclusters of galaxies at high redshifts. We study (i) the standard cold dark matter (CDM) model, (ii) a modifie d CDM model with less power at small scales, and (iii) a Lambda + CDM model in a universe with Omega(0), + Omega(Lambda), = 1. We show that it should be possible for the next generation of radio telescopes to d etect such structures at a redshift of 3.34 with an integration of abo ut 100 h. We also discuss possible schemes for enhancing signal-to-noi se ratio to detect protocondensates at high redshifts.