Camera, Stefano, Santos, Mario G., Bacon, David J., Jarvis, Matt J., McAlpine, Kim, Norris, Ray P., Raccanelli, Alvise and Roettgering, Huub (2012), "Impact of redshift information on cosmological applications with
next-generation radio surveys", MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 427, 3: 2079-2088.
Abstract: In this paper, we explore how the forthcoming generation of large-scale
radio continuum surveys, with the inclusion of some degree of redshift
information, can constrain cosmological parameters. By cross-matching
these radio surveys with shallow optical to near-infrared surveys, we
can essentially separate the source distribution into a low- and a
high-redshift sample, thus providing a constraint on the evolution of
cosmological parameters such as those related to dark energy. We examine
two radio surveys, the Evolutionary Map of the Universe (EMU) and the
Westerbork Observations of the Deep APERTIF Northern sky (WODAN). A
crucial advantage is their combined potential to provide a deep,
full-sky survey. The surveys used for the cross-identifications are
SkyMapper and Sloan Digital Sky Survey, for the southern and northern
skies, respectively. We concentrate on the galaxy clustering angular
power spectrum as our benchmark observable, and find that the
possibility of including such low-redshift information yields major
improvements in the determination of cosmological parameters. With this
approach, and provided a good knowledge of the galaxy bias evolution, we
are able to put strict constraints on the dark energy parameters, i.e.
w0 = -0.9 +/- 0.041 and wa = -0.24 +/- 0.13, with Type Ia supernovae and
cosmic microwave background priors (with a one-parameter bias in this
case); this corresponds to a Figure of Merit (FoM) >600, which is twice
better than what is obtained by using only the cross-identified sources
and greater than four time better than the case without any redshift
information at all.
Keywords: cosmological parameters; cosmology: observations; large-scale structure
of universe; radio continuum: galaxies
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