First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: The Angular Power Spectrum

By Gary F. Hinshaw, David N. Spergel, L. Verde, R. Hill, S. Meyer, C. Barnès, C. Bennett, Mark Halpern, N. Jarosik, Alan Kogut and 13 more. 2003

734 citations recorded by the source corpus.

We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are robust. The data are modestly contaminated by diffuse Galactic foreground emission, but we show that a simple Galactic template model is sufficient to remove the signal. Point sources produce a modest contamination in the low-frequency data. After masking ∼700 known bright sources from the maps, we estimate that residual sources contribute ∼3500 μK2 at 41 GHz and ∼130 μK2 at 94 GHz to the power spectrum [ℓ(ℓ + 1)Cℓ/2π] at ℓ = 1000. Systematic errors are negligible compared to the (modest) level of foreground emission. Our best estimate of the power spectrum is derived from 28 cross-power spectra of statistically independent channels. The final spectrum is essentially independent of the noise properties of an individual radiometer. The resulting spectrum provides a definitive measurement of the cosmic microwave background (CMB) power spectrum, with uncertainties limited by cosmic variance, up to ℓ ∼ 350. The spectrum clearly exhibits a first acoustic peak at ℓ = 220 and a second acoustic peak at ℓ ∼ 540 (Page and coworkers), and it provides strong support for adiabatic initial conditions (Spergel and coworkers). Kogut and coworkers analyze the C power spectrum and present evidence for a relatively high optical depth and an early period of cosmic reionization. Among other things, this implies that the temperature power spectrum has been suppressed by ∼30% on degree angular scales, as a result of secondary scattering.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/600c6f0f32ffa37f83e67f8eafec6ef2de7c88ca

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Citations in the corpus

Evidence of Vorticity and Shear at Large Angular Scales in the WMAP Data: A Violation of Cosmological Isotropy? (2005, methodology): “10 The WMAP team (Hinshaw et al. 2003) use data solely from the V- and W-bands over the spectral range ℓ < 100.”
The 2dF Galaxy Redshift Survey: spherical harmonics analysis of fluctuations in the final catalogue (2004, background): “The use c© 0000 RAS of large scale structure as a cosmological probe has acquired an increased importance in the new era of high precision cosmology, which follows high-quality measurements of the cosmic microwave background (CMB) power spectrum (Bennett et al. 2003; Hinshaw et al. 2003).”
FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: ANGULAR POWER SPECTRA (2008, methodology): “Our basic analysis approach is similar to the approach described in our first year WMAP temperature analysis (Hinshaw et al. 2003) and polarization analysis (Kogut et al. 2003) and in the three year WMAP temperature (Hinshaw et al. 2007) and polarization analysis (Page et al. 2007).”
Limits on non-Gaussianities from WMAP data (2005, background): “The full inversion of the covariance matrix is computationally rather cumbersome (although doable as the matrix is with good approximation block diagonal [22]).”
Large-Angle Anomalies in the CMB (2010, background): “Extraordinary full-sky temperature maps produced by the Wilkinson Microwave Anisotropy Probe (WMAP), in particular, are revolutionizing our ability to probe the universe on its largest scales [1–6].”
First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications For Inflation (2003, methodology): “We use the WMAP TT (Hinshaw et al. 2003) and TE (Kogut et al. 2003) angular power spectra.”
Exotic solutions in General Relativity: Traversable wormholes and 'warp drive' spacetimes (2007, background): “Evidence of this cosmological expansion, coming from measurements of supernovae of type Ia (SNe Ia) [149, 150] and independently from the cosmic microwave background radiation [151, 152], shows that the Universe additionally consists of some sort of negative pressure “dark energy”.”
First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission (2003, neutral): “See Hinshaw et al. (2003) for the power spectra before and after the template subtraction.”
The 2dF Galaxy Redshift Survey: power-spectrum analysis of the final data set and cosmological implications (2005, methodology): “We have used the Markov-Chain Monte-Carlo (MCMC; Lewis & Bridle 2002) method to fit cosmological models to our new power-spectrum data combined with WMAP year 1 (Hinshaw et al. 2003) CMB data.”
Planck intermediate results: LI. features in the cosmic microwave background temperature power spectrum and shifts in cosmological parameters (2016, positive): “Indeed, “anomalies” related to the low-`’s have been discussed extensively in the literature, for example the low quadrupole or the localized “dip” near `' 20 (Bennett et al. 1996; Hinshaw et al. 2003; Spergel et al. 2003; Peiris et al. 2003; Mortonson et al. 2009; Cai et al. 2015b).”