Wilkinson Microwave Anisotropy Probe DR2

The data made available through this page has been updated. The most recent version of this data may be accessed through https://lambda.gsfc.nasa.gov/product/wmap/current/

TT Power Spectra (includes binned version)

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The 3-yr TT power spectrum is produced by combining the Maximum Likelihood estimated spectrum from l = 2-10 with the pseudo-Cl based cross-power spectra for l > 10. The pseudo-Cl estimate uses only V- and W-band data, with a uniform pixel weight applied for l≤500 and "Nobs" weights for l > 500. A total of 153 individual cross-power spectra are formed from the three individual years of data and six V- and W-band differencing assemblies.

The complete (unbinned) TT power spectrum data are provided as an ASCII table containing the following columns:

  • the multipole moment l
  • the power spectrum in units of uK2
  • the corresponding diagonal elements of the covariance matrix
  • the portion of the diagonal element of the covariance matrix attributed to measurement errors
  • the portion of the diagonal element of the covariance matrix attributed to cosmic variance, assuming the best-fit LCDM model described in Spergel et al. (2006).

The diagonal elements provide an estimate of the error, but should not be used as exact error bars. The complete Fisher matrix should be used for that purpose.

A binned version of the power spectrum is also available, in a separate file whose format and content are similar to those described above for the unbinned data. The choice of l bins is the same as that used in e.g., Figure 16 of Hinshaw et al. (see below).

Additional Information

A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Alan P. Smale
LAMBDA Director: Dr. Thomas M. Essinger-Hileman
NASA Official: Dr. Thomas M. Essinger-Hileman
Web Curator: Mr. Michael R. Greason