The images below represent full-sky maps of the cosmic microwave background anisotropy and foreground signal from our galaxy (in red). The 5 frequency maps are constructed from the differential time-ordered observations of the ten WMAP differencing assemblies. Galactic foreground is stongest in K band, weakest in V and W bands.
Maps of observed polarization intensity ( P = sqrt(Q^2 + U^2) ) and direction (gamma = 0.5*arctan(U/Q)) for the five WMAP frequency bands. Color is used to specify the magnitude of P and arrows indicate direction. The length of the arrow is logarithmically dependent on the magnitude of P. The maps are smoothed to 2 degrees. The dominant polarization signal is Galactic in origin. See Page etal (2006) for further details.
Stokes Q and U maps constructed from WMAP Three-year K and Ka band observations, smoothed to 1 degree. The Galactic plane is dominated by positive Stokes Q because the foreground polarization direction is perpendicular to the plane. For comparison, the Stokes Q and U maps of a noiseless CMB simulation have peak-to-peak values of less than 6 uK.
Temperature and polarization power spectra derived from the WMAP Three-year data. Data are represented as points, curves correspond to the best-fit LCDM model, and shaded regions delineate cosmic variance about the model.
The Internal Linear Combination Map is a weighted linear combination of the five WMAP frequency maps. The weights are computed using criteria which minimize the Galactic foreground contribution to the sky signal. The resultant map provides a low-contamination image of the CMB anisotropy.
Three-color maps from the Maximum Entropy Method (MEM) model for the 5 WMAP frequency bands. These maps indicate which emission mechanism dominates as a function of frequency and sky position. Synchrotron is red, free-free is green, and thermal dust is blue.
A guide to the microwave sky for reference. This picture shows the large-scale emission from the Milky Way galaxy, including some of its notable components such as the Cygnus complex, the North Polar Spur, the Gum region, etc. The small circles show positions of significant microwave point sources. The brighter sources are labeled for reference.
WMAP uses a set of standard sky masks for certain data processing and analysis needs. The masking is based on the K-band signal levels, which each successive mask increasing the severity of the masking cut. The most severe cut is Kp0. Not shown are additional cuts made around point sources.