SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE ( WMAP ) OBSERVATIONS: POWER SPECTRA AND WMAP -DERIVED PARAMETERS

(Abridged) We present the angular power spectra derived from the 7-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone. The third acoustic peak in the TT spectrum is now well measured by WMAP. In the context of a flat LambdaCDM model, this improvement allows us to place tighter constraints on the matter density from WMAP data alone, and on the epoch of matter-radiation equality, The temperature-polarization (TE) spectrum is detected in the 7-year data with a significance of 20 sigma, compared to 13 sigma with the 5-year data. The low-l EE spectrum, a measure of the optical depth due to reionization, is detected at 5.5 sigma significance when averaged over l = 2-7. The…