Neutral hydrogen at high redshifts as a probe of structure formation - III. Radio maps from TV-body simulations

Large inhomogeneities in neutral hydrogen in the universe can be detected atredshifts $z \leq 10$ using the redshifted 21 cm line emission. We usecosmological N-Body simulations for dark matter and a simple model for baryoniccollapse to estimate the signal expected from structures like proto-clusters ofgalaxies at high redshifts. We study: (i) the standard CDM model, (ii) amodified CDM model with less power at small scales, and (iii) a $\Lambda+$CDMmodel in a universe with $\Omega_0 + \Omega_\Lambda = 1$. We show that itshould be possible for the next generation radio telescopes to detect suchstructures at the redshift 3.34 with an integration of about 100 hours. We alsodiscuss possible schemes for enhancing signal to noise ratio to detectproto-condensates at high redshifts.Comment: 9 pages, six figures. Revised versio