CLASS 90 GHz 2021-2024 Power Spectra

EE Power Spectra

The power spectrum data are provided in three separate files:

(1) class_midell_binned_Cl_EE.txt, and

(2) class_midell_binned_Cl_EE_wide.txt:

CLASS-only (binned) CMB EE band power in the multipole range 31 ≤ ℓ< 301. The two provided files differ only in the choice of bin width. The first file uses Δℓ = 10, and the "wide" version uses Δℓ = 18.

Details:

Four time-interleaved CLASS data splits are cleaned for synchrotron and dust foregrounds. Two sets of foreground templates are used:
i) WMAP K-band and Planck 353 ds1 (Sroll2).
ii) Planck 30 GHz (PR4) and Planck 353 ds2 (Sroll2).
The CLASS CMB spectrum is obtained by averaging all cross correlation of the four splits, with maps for each split cleaned with different foreground template sets to avoid noise bias. The power spectrum has been corrected for beam window functions and the filtering transfer function in the harmonic space. The uncertainty estimates include instrumental noise (from CLASS and template maps) and the sample variance from the best-fit cosmology.

(3) classxplanck_lowell_Cl_EE.txt:

Low-ell CMB EE band power from cross-correlation of CLASS 90 GHz and Planck 100/143 coadded map. The single multipole spectrum is provided in the range 2 ≤ ℓ ≤ 30.

Details:

The cross power spectrum is obtained following the description in Li et al., 2025. The CLASS 90 GHz polarization maps are cleaned for synchrotron and dust using (filtered) WMAP K-band and Planck 353 GHz maps (Sroll2, ds1). The Planck (Sroll2) 100 and 143 GHz maps are cleaned with Planck (PR4) 30 GHz and Planck 353 GHz maps (Sroll2, ds2). The Planck foreground-cleaned 100/143 maps are minimum-variance coadded to perform the cross correlation. The power spectrum is taken with a customized version of the xQML estimator, which self-consistently accounts for the filtering bias using the pixel-space transfer matrix.

All power spectrum data are provided in units of uK²_CMB and sample variance from the best-fit cosmology is included in the error bars.

Additional Information:

A Measurement of the Largest-Scale CMB E-mode Polarization with CLASS Li et al. (2025)

Class Product Table