Analysis of differential observations of the cosmological radio
  background : studying the SZE-21cm
  In pursuit of understanding the early Universe and early processes occurring
particularly in the Dark Ages (DA) and the Epoch of Reionization (EoR), it is
vital that a suitable probe is identified. Probing these epochs will be useful
in studies of the origin of first galaxies and most importantly formation of
early black-holes. Over the past decade numerous probes have been proposed,
with one of the most promising being the SZE-21cm, a specific form of the
Sunyaev-Zeldovich effect (SZE) produced when photons of the 21cm background are
inverse Compton up-scattered by electrons residing in hot plasma of cosmic
structures such as galaxy clusters and active radio galaxies. The SZE-21cm is
calculated in a full relativistic approach of the scattering processes of the
CMB photons modified by the cosmological redshifted 21cm background in the hot
intra-cluster medium of galaxy clusters capturing effects induced by
relativistic corrections to this scattering and by multiple scattering effects.
We apply image differencing techniques to simulated radio observations of
galaxy clusters using the redshifted 21cm background, we conduct this making
use of the public semi-numeric code 21cmFAST. We are able to achieve
subtraction of contaminating foregrounds through pixel by pixel operations on
the data retrieved from our simulated data cubes. We demonstrate that SZE-21cm
can be recovered through differential observations of the 21cm background.
