Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Temperature Analysis

By Gary F. Hinshaw, M. Nolta, C. Bennett, R. Bean, O. Dor'e, M. Greason, Mark Halpern, R. Hill, N. Jarosik, Alan Kogut and 12 more. 2006

882 citations recorded by the source corpus.

We present new full-sky temperature maps in five frequency bands from 23 to 94 GHz, based on data from the first 3 years of the WMAP sky survey. The new maps are consistent with the first-year maps and are more sensitive. The 3 year maps incorporate several improvements in data processing made possible by the additional years of data and by a more complete analysis of the polarization signal. These include several new consistency tests as well as refinements in the gain calibration and beam response models. We employ two forms of multifrequency analysis to separate astrophysical foreground signals from the CMB, each of which improves on our first-year analyses. First, we form an improved "Internal Linear Combination" (ILC) map, based solely on WMAP data, by adding a bias-correction step and by quantifying residual uncertainties in the resulting map. Second, we fit and subtract new spatial templates that trace Galactic emission; in particular, we now use low-frequency WMAP data to trace synchrotron emission instead of the 408 MHz sky survey. The WMAP point source catalog is updated to include 115 new sources whose detection is made possible by the improved sky map sensitivity. We derive the angular power spectrum of the temperature anisotropy using a hybrid approach that combines a maximum likelihood estimate at low l (large angular scales) with a quadratic cross-power estimate for l > 30. The resulting multifrequency spectra are analyzed for residual point source contamination. At 94 GHz the unmasked sources contribute 128 ± 27 μK2 to l(l + 1)Cl/2π at l = 1000. After subtracting this contribution, our best estimate of the CMB power spectrum is derived by averaging cross-power spectra from 153 statistically independent channel pairs. The combined spectrum is cosmic variance limited to l = 400, and the signal-to-noise ratio per l-mode exceeds unity up to l = 850. For bins of width Δl/l = 3%, the signal-to-noise ratio exceeds unity up to l = 1000. The first two acoustic peaks are seen at l = 220.8 ± 0.7 and l = 530.9 ± 3.8, respectively, while the first two troughs are seen at l = 412.4 ± 1.9 and l = 675.2 ± 11.1. The rise to the third peak is unambiguous; when the WMAP data are combined with higher resolution CMB measurements, the existence of a third acoustic peak is well established. Spergel et al. use the 3 year temperature and polarization data to constrain cosmological model parameters. A simple six-parameter ΛCDM model continues to fit CMB data and other measures of large-scale structure remarkably well. The new polarization data produce a better measurement of the optical depth to reionization, τ = 0.089 ± 0.03. This new and tighter constraint on τ helps break a degeneracy with the scalar spectral index, which is now found to be ns = 0.960 ± 0.016. If additional cosmological data sets are included in the analysis, the spectral index is found to be ns = 0.947 ± 0.015.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/bf697c14fe5fc7fe1e56ae6cfe62e0f1a7561177

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Citations in the corpus

POWER ASYMMETRY IN COSMIC MICROWAVE BACKGROUND FLUCTUATIONS FROM FULL SKY TO SUB-DEGREE SCALES: IS THE UNIVERSE ISOTROPIC? (2008, background): “Some of these have been confirmed again in the 3 and 5 year data (Hinshaw et al. 2007; Spergel et al. 2006; Cruz et al. 2006; McEwen et al. 2006; Eriksen et al 2007; Pietrobon et al. 2008).”
Component separation methods for the PLANCK mission (2008, methodology): “…The analysis leading to the WMAP cosmological parameter estimation involves foreground cleaning by template subtraction, masking of the most contaminated 15% of sky, and subtracting a model of the contribution of unresolved point sources from the CMB cross power spectra (Hinshaw et al. 2003, 2007).”
SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION (2010, methodology): “The calibration errors quoted above are much greater than the calibration uncertainty of the WMAP 5- year data (0.2% Hinshaw et al. 2007).”
NINE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: FINAL MAPS AND RESULTS (2012, methodology): “Algorithmic details and underlying concepts are set forth in Hinshaw et al. (2007).”
SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) OBSERVATIONS: PLANETS AND CELESTIAL CALIBRATION SOURCES (2010, background): “The WMAP project routinely compiles and distributes a point source catalog, which tabulates mean flux values in those same five passbands for bright sources off the Galactic plane (Wright et al. 2009; Hinshaw et al. 2007; Bennett et al. 2003a).”
Extragalactic optical-infrared background radiation, its time evolution and the cosmic photon-photon opacity (2008, background): “The major contributor to the background photon flux, the CMB, has been extremely well characterized both spectrally (Mather et al. 1994) and spatially (Hinshaw et al. 2007), and has been shown to be a very isotropic pure black-body spectrum.”
FIVE-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE OBSERVATIONS: COSMOLOGICAL INTERPRETATION (2008, neutral): “…of the point source correction, Aps = 0.011± 0.001 µK2 sr (Nolta et al. 2008), is slightly lower than the 3-year estimate, Aps = 0.014 ± 0.003 µK2 sr (Hinshaw et al. 2007), partly because more sources have been detected and masked by the 5-year source mask (390 sources have been detected in the…”
Inflation after WMAP3: confronting the slow-roll and exact power spectra with CMB data (2006, background): “ and marginalised probability exhibits narrow peaks on particular frequencies only thereby leading to a discrete set of best ﬁt submanifolds in the parameter space. From the WMAP team likelihood code [1, 2, 3, 4], the best ﬁt associated with the highest resonance peak leads to an overall χ2 = 11239.”