CBI Data Products - CBI Total Intensity Observations 2000-2005

Here we present supplementary numerical data for the CBI polarization observations reported by J. L. Sievers et al. If you use these data in a publication, please cite the appropriate papers and also give the URL of this web page and the date of publication (given at the bottom of the page).

The spectrum is contained in CBI09.newdat This data file should work as-is with current versions of COSMOMC (Lewis & Bridle, 2002)

File format:

  • first line - location of window functions (should be properly set).
  • second line - total bands in each polarization. Order is TT,EE,BB,TB,TE,EB
  • next lines (BAND_SELECTION) - select which bands are to be used in parameter fitting. We drop bands where WMAP5 is cosmic-variance limited.
  • next line: (1 1.00 0.020) - only number of relevance is 0.020, which is the CBI calibration uncertainty in power (1.0% in amplitude) (ignorable line).
    iliketype - COSMOMC/.newdat format support offset-lognormal approximation to the likelihood (Bond, Jaffe, and Knox 2000).
  • iliketype=1 specifies the use of the offset-lognormal approximation.
  • Next is a block for each polarization in the file. This file contains only a TT power spectrum, and so there is only a single block here. This contains the name of the polarization, then one line containing the spectrum for each band power in the polarization. The fields are:
  • 1) Band #
    2) Power spectrum (l(l+1)C_l/2pi, in uK2)
    3) Gaussian error bar
    4) Estimate of faint source contribution to the bin.
    5) noise spectrum, used in the offset-lognormal approximation.
    6) and 7) the lower/upper ell range contained in the band.

  • Then a block containing the same-band correlations between band-powers. Ones along the diagonal,
    with the off-diagonal terms the degree of correlation between bands.
  • Finally, the Fisher matrix for the entire spectrum. Units are in uK4.
    This full matrix is used when calculating the likelihood of a spectrum in COSMOMC.
  • There are also files that contain the band-power window functions. There is one file for each band. Columns are:
  • 1) ell
    2) W_ell/ell for. Columns are normalized, so expected C_ell is sum(W_ell)C_ell over ell.

The above information is taken from this CBI page. published on 2009-01-28

Additional Details:

* Sievers et al. (2009), "Cosmological Results from Five Years of 30 GHz CMB Intensity Measurements with the
Cosmic Background Imager", arXiv:0901.4540. ADS

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