A high-resolution self-consistent whole sky foreground model
  The neutral hydrogen 21cm line is potentially a very powerful probe of the
observable universe, and a number of on-going experiments are trying to detect
it at cosmological distances. However, the presence of strong foreground
radiations such as the galactic synchrotron radiation, galactic free-free
emission and extragalactic radio sources make it a very challenging task. For
the design of 21cm experiments and analysis of their data, simulation is an
essential tool, and good sky foreground model is needed. With existing data the
whole sky maps are available only in low angular resolutions or for limited
patches of sky, which is inadequate in the simulation of these new 21cm
experiments. In this paper, we present the method of constructing a high
resolution self-consistent sky model at low frequencies, which incorporates
both diffuse foreground and point sources. Our diffuse map is constructed by
generating physical foreground components including the galactic synchrotron
emission and galactic free-free emission. The point source sample is generated
using the actual data from the NRAO VLA Sky Survey (NVSS) and the Sydney
University Molonglo Sky Survey (SUMSS) where they are available and complete in
flux limit, and mock point sources according to statistical distributions. The
entire model is made self-consistent by removing the integrated flux of the
point sources from the diffuse map so that this part of radiation is not double
counted. We show that with the point sources added, a significant angular power
is introduced in the mock sky map, which may be important for foreground
subtraction simulations. Our sky maps and point source catalogues are available
to download.
