2DARK天文志

Abstract: A number of large current experiments aim to detect the signatures of the
Cosmic Reionization at redshifts z>6. Their success depends crucially on
understanding the character of the reionization process and its observable
consequences and designing the best strategies to use. We use large-scale
simulations of cosmic reionization to evaluate the reionization signatures at
redshifted 21-cm and small-scale CMB anisotropies in the best current model for
the background universe, with fundamental cosmological parameters given by WMAP
3-year results (WMAP3). We find that the optimal frequency range for observing
the ``global step'' of the 21-cm emission is 120-150 MHz, while statistical
studies should aim at 140-160 MHz, observable by GMRT. Some
strongly-nongaussian brightness features should be detectable at frequencies up
to ~190 MHz. In terms of sensitivity-signal trade-off relatively low
resolutions, corresponding to beams of at least a few arcminutes, are
preferable. The CMB anisotropy signal from the kinetic Sunyaev-Zel'dovich
effect from reionized patches peaks at tens of muK at arcminute scales and has
an rms of ~1 muK, and should be observable by the Atacama Cosmology Telescope
and the South Pole Telescope. We discuss the various observational issues and
the uncertainties involved, mostly related to the poorly-known reionization
parameters and, to a lesser extend, to the uncertainties in the background
cosmology.