FirstYear Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Parameter Estimation Methodology
Abstract
We describe our methodology for comparing the Wilkinson Microwave Anisotropy Probe (WMAP) measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data and the tight constraints on cosmological parameters that are derived require a rigorous analysis so that the approximations made in the modeling do not lead to significant biases. We describe our use of the likelihood function to characterize the statistical properties of the microwave background sky. We outline the use of the Monte Carlo Markov Chains to explore the likelihood of the data given a model to determine the bestfit cosmological parameters and their uncertainties. We add to the WMAP data the l>~700 Cosmic Background Imager (CBI) and Arcminute Cosmology Bolometer Array Receiver (ACBAR) measurements of the CMB, the galaxy power spectrum at z~0 obtained from the TwoDegree Field Galaxy Redshift Survey (2dFGRS), and the matter power spectrum at z~3 as measured with the Lyα forest. These last two data sets complement the CMB measurements by probing the matter power spectrum of the nearby universe. Combining CMB and 2dFGRS requires that we include in our analysis a model for galaxy bias, redshift distortions, and the nonlinear growth of structure. We show how the statistical and systematic uncertainties in the model and the data are propagated through the full analysis.
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:
 10.1086/377335
 arXiv:
 arXiv:astroph/0302218
 Bibcode:
 2003ApJS..148..195V
 Keywords:

 Cosmology: Cosmic Microwave Background;
 Cosmology: Cosmological Parameters Cosmology: Observations;
 Methods: Data Analysis;
 Methods: Statistical;
 Astrophysics
 EPrint:
 Replaced with version with final edits for ApJ. One of thirteen companion papers on firstyear WMAP results