This page provides data products associated with the SPT-3G D1 measurement of the CMB TT, TE, and EE power spectra, as described in Camphuis et al. 2025.

The SPT-3G D1 data set comprises observations from 2019 and 2020 of the SPT-3G Main field, covering the 95, 150, and 220 GHz frequency bands.

The released data include TT band powers spanning the angular multipole range 400 < ℓ < 3000, and TE/EE band powers covering 400 < ℓ < 4000. All spectra are binned into band powers of width Δℓ = 50. These data provide the most precise measurements of the TE and EE band powers at 2200 < ℓ < 4000, and 1800 < ℓ < 4000, respectively (at the time of release).

If you have any questions regarding this data set or its use, please contact Etienne Camphuis, Wei Quan, Lennart Balkenhol and Ali R. Khalife (etienne_dot_camphuis_at_iap_dot_fr, weiquan_at_uchicago_dot_edu, lennart_dot_balkenhol_at_iap_dot_fr, ridakhal_at_iap_dot_fr)

We provide the foreground- and nuisance-subtracted minimum-variance combination of the SPT-3G D1 multi-frequency band powers for plotting purposes only, such as reproducing the figure below. The band powers, band power errors (both in D_ℓ in units of μK²), and associated band centers are provided in 3 separate text files for TT, TE, and EE spectra: Download band powers (ZIP).

Each row in the files corresponds to one ℓ-bin. The columns are:
(1) ℓ_b, (2) D_b, (3) σ_b

See the figure below for a visual representation of these band powers.

TT, TE, and EE band powers from SPT-3G D1 (blue dots), ACT DR6 (orange empty squares) and Planck PR3 (green empty dots).
Band powers from each experiment are foreground- and nuisance-parameter cleaned combinations of all auto- and cross-frequency spectra.
We also show the best-fit LCDM model to SPT bandpowers (solid line).
Top: TT and EE band powers on a logarithmic scale.
SPT TT band powers are estimated in the multipole range ℓ = 400 to 3000, while the range for TE and EE band powers is ℓ = 400 to 4000.
Bottom: TE band powers in linear scale, with a zoomed-in view of the ℓ > 2000 region where ground-based experiments dominate the measurement.
These data sets demonstrate excellent agreement with each other, and the SPT-3G D1 data provide the tightest measurement of the lensed EE and TE band powers at ℓ = 1800-4000 and ℓ = 2200-4000, respectively.

The likelihood code for the SPT-3G D1 TT, TE, and EE band powers is based on candl, a differentiable likelihood framework for analysing CMB power spectrum measurements.

We provide the SPT-3G D1 candl library at https://github.com/SouthPoleTelescope/spt_candl_data/tree/main, along with tutorial notebooks and sampler templates.

Both the multi-frequency band powers likelihood code and the lite version of the likelihood code, called SPT-lite, are available.