FirstYear Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Interpretation of the TT and TE Angular Power Spectrum Peaks
Abstract
The CMB has distinct peaks in both its temperature angular power spectrum (TT) and temperaturepolarization crosspower spectrum (TE). From the WMAP data we find the first peak in the temperature spectrum at l=220.1+/0.8 with an amplitude of 74.7+/0.5μK the first trough at l=411.7+/3.5 with an amplitude of 41.0+/0.5μK and the second peak at l=546+/10 with an amplitude of 48.8+/0.9μK. The TE spectrum has an antipeak at l=137+/9 with a crosspower of 35+/9μK^{2}, and a peak at l=329+/19 with crosspower 105+/18μK^{2}. All uncertainties are 1 σ and include calibration and beam errors.
An intuition for how the data determine the cosmological parameters may be gained by limiting one's attention to a subset of parameters and their effects on the peak characteristics. We interpret the peaks in the context of a flat adiabatic ΛCDM model with the goal of showing how the cosmic baryon density, Ω_{b}h^{2}, matter density, Ω_{m}h^{2}, scalar index, n_{s}, and age of the universe are encoded in their positions and amplitudes. To this end, we introduce a new scaling relation for the TE antipeaktopeak amplitude ratio and recompute known related scaling relations for the TT spectrum in light of the WMAP data. From the scaling relations, we show that WMAP's tight bound on Ω_{b}h^{2} is intimately linked to its robust detection of the first and second peaks of the TT spectrum.
WMAP is the result of a partnership between Princeton University and the NASA Goddard Space Flight Center. Scientific guidance is provided by the WMAP Science Team.
 Publication:

The Astrophysical Journal Supplement Series
 Pub Date:
 September 2003
 DOI:
 10.1086/377224
 arXiv:
 arXiv:astroph/0302220
 Bibcode:
 2003ApJS..148..233P
 Keywords:

 Cosmology: Cosmic Microwave Background;
 Cosmology: Cosmological Parameters;
 Cosmology: Observations;
 Cosmology: LargeScale Structure of Universe;
 Astrophysics
 EPrint:
 Replaced with version accepted by ApJ. One of 13 companion papers on firstyear WMAP results