1996/01/12 by C. L. Bennett, A. Banday, K. M. Gorski +7 · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/310075
published as Astrophys.J.464:L1-L4,1996 · 11 pages plus 2 PostScript figures. Figures 2 and 4 are not included, but are available upon request to [email protected]. Submitted to The Astrophysical Journal (Letters)
arxiv created 1996/01/12 · arxiv updated 2009/12/01
The cosmic microwave background radiation provides unique constraints on cosmological models. In this Letter we present a summary of the spatial properties of the cosmic microwave background radiation based on the full 4 years of COBE DMR observations, as detailed in a set of companion Letters. The anisotropy is consistent with a scale-invariant power law model and Gaussian statistics. With full use of the multi-frequency 4-year DMR data, including our estimate of the effects of Galactic emission, we find a power-law spectral index of n=1.2± 0.3 and a quadrupole normalization Qrms-PS=15.3+3.8-2.8 μK. For n=1 the best-fit normalization is Qrms-PS\vertn=1=18± 1.6 μK. These values are consistent with both our previous 1-year and 2-year results. The results include use of the ℓ=2 quadrupole term; exclusion of this term gives consistent results, but with larger uncertainties. The 4-year sky maps, presented in this Letter, portray an accurate overall visual impression of the anisotropy since the signal-to-noise ratio is ~2 per 10 degree sky map patch. The improved signal-to-noise ratio of the 4-year maps also allows for improvements in Galactic modeling and limits on non-Gaussian statistics.