First Year Wilkinson Microwave Anisotropy Probe Observations: Dark Energy Induced Correlation with Radio Sources
Abstract
The firstyear Wilkinson Microwave Anisotropy Probe (WMAP) data, in combination with any one of a number of other cosmic probes, show that we live in a flat Λdominated cold dark matter (CDM) universe with Ω_{m}~0.27 and Ω_{Λ}~0.73. In this model the latetime action of the dark energy, through the integrated SachsWolfe effect, should produce cosmic microwave background (CMB) anisotropies correlated with matter density fluctuations at z<~2 (Crittenden & Turok 1996). The measurement of such a signal is an important independent check of the model. We crosscorrelate the NRAO VLA Sky Survey (NVSS) radio source catalog (Condon et al. 1998) with the WMAP data in search of this signal, and see indications of the expected correlation. Assuming a flat ΛCDM cosmology, we find Ω_{Λ}>0 (95% CL, statistical errors only) with the peak of the likelihood at Ω_{Λ}=0.68, consistent with the preferred WMAP value. A closed model with Ω_{m}=1.28, h=0.33, and no dark energy component (Ω_{Λ}=0), marginally consistent with the WMAP CMB TT angular power spectrum, would produce an anticorrelation between the matter distribution and the CMB. Our analysis of the crosscorrelation of the WMAP data with the NVSS catalog rejects this cosmology at the 3 σ level.
 Publication:

The Astrophysical Journal
 Pub Date:
 June 2004
 DOI:
 10.1086/386536
 arXiv:
 arXiv:astroph/0305097
 Bibcode:
 2004ApJ...608...10N
 Keywords:

 Cosmology: Cosmic Microwave Background;
 Cosmology: Observations;
 Astrophysics
 EPrint:
 13 pages, 4 figures, submitted to ApJ