CBI Temperature and Polarization Observations 2002-2005
This file contains the fine-binned CBI polarization bandpowers and
band-power Fisher matrix needed for doing parameter analysis with
the CBI power spectrum. It is formatted for use with COSMOMC.
System requirements: There are no special system requirements - everything is
saved as text files. It is formatted for use with COSMOMC, but can be
easily modified by the user if other formats are required.
The spectrum is contained in CBIpol_2.0_final.newdat
This data file should work as-is with current versions of COSMOMC
(Lewis & Bridle, 2002)
- 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.
As mentioned in the paper, we drop the lowest T bin (both in TT and TE).
- next line: (1 1.00 0.026) - only number of relevance is 0.026, which is the CBI calibration
uncertainty in power (1.3% in amplitude) (ignorable line) iliketype - COSMOMC/.newdat format support offset-lognormal
approximation to the likelihood (Bond, Jaffe, and Knox 2000).
iliketype=2 lets the use of the offset-lognormal
approximation be specified for each band individually. We turn it on for TT, EE, and BB, and turn it off for TE.
- Next is a block for each polarization in the file. 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) and 4) - error bars.
5) noise spectrum, used in the offset-lognormal approximation.
6) and 7) the lower/upper ell range contained in the band.
8) the iliketype flag for the band. 1 means use offset-lognormal, 0 means Gaussian.
- 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 (all polarizations). 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:
2)-5) W_ell/ell for each polarization. Columns are normalized, so expected C_ell is sum(W_ell,PP')C_ell,PP' over ell and
The above information is taken from this CBI page, published on 2006-11-07, and from the ReadMe file in the ApJ online supplement.
* Sievers et al. (2007), "Implications of the Cosmic Background Imager Polarization Data", ApJ, 660, 976. ADS
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