Js. Bagla et al., NEUTRAL HYDROGEN AT HIGH REDSHIFTS AS A PROBE OF STRUCTURE FORMATION .3. RADIO MAPS FROM N-BODY SIMULATIONS, Monthly Notices of the Royal Astronomical Society, 289(3), 1997, pp. 671-680
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.