IAU01426
Presentation type requested: EITHER
COSMOLOGY FROM WIDE-AREA RADIO SURVEYS
Chris Blake
University of New South Wales
Wide-area radio surveys provide a large-scale map of the cosmos undimmed by dust extinction, out to very high redshift. Radio galaxies are effective tracers of mass, hosted by massive elliptical galaxies, delineating clusters and superclusters. We have quantified the projected distribution of radio AGN using the NVSS radio survey of over a million sources at 1.4 GHz. Over large angular scales we detect the imprint of the 1 per cent velocity dipole predicted by the standard cosmological model. The direction of the dipole agrees with that identified in the CMB and the amplitude is consistent with special relativity. On smaller angular scales we measure radio galaxy clustering using a variety of techniques. Adopting a reasonable model for the redshift distribution, the clustering length of radio AGN is about 11 Mpc at z=0, consistent with their nature as luminous elliptical galaxies. The angular power spectrum probes spatial clustering on large scales, constraining the amplitude and slope of the 3D power spectrum in a manner independent of CMB measurements.
Wall Jasper
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