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SouthPole Site
Observing & Analysis
SPT Team
News & Publications
Internal pages

Project Supported by

NSF, National Science Foundation

KICP, Kavli Institute for Cosmological Physics

USAP, United States Antarctic Program

Antarctic Support Contract (ASC)

DOE Office of Science High Energy Physics

Related Websites

CBI, Cosmic Background Imager

DASI, Degree Angular Scale Interferometer

WMAP, Wilkinson Microwave Anisotropy Probe


Likelihood Code
CosmoPower Models



This page provides data products associated with the SPT-3G 2018 measurement of the CMB TT, TE, and EE power spectrum measurement over 1500 square degrees described in Balkenhol et al. 2022, arXiv:2212.05642. The TT power spectra cover the angular multipole range 750 < ell <= 3000, whereas the TE and EE spectra cover 300 < ell <= 3000. The power spectrum measurement is binned into band powers of width delta_ell=50 for ell<=2000 and delta_ell=100 for ell>2000. The data products here update the results of Dutcher et al. 2021, arXiv:2101.01684, and Balkenhol et al. 2021, arXiv:2103.13618.

If you have any questions regarding this data set or its use, please contact Lennart Balkenhol (lennart_dot_balkenhol_at_iap_dot_fr).




Individual figures are available in PDF format here or bundled in a ZIP file here. We highlight selected figures below.

SPT-3G 2018 minimum-variance TT/TE/EE band powers (black) along with a selection of contemporary power spectrum measurements: Planck (blue) (Planck results 2018 V), SPT-SZ (green, top panel only) (Mocanu et al. 2019), SPTpol (green, bottom two panels only, horizontally offset for clarity) (Henning et al. 2018), ACT DR4 (orange) (Choi et al. 2020), POLARBEAR (pink, bottom panel only) (Adachi et al. 2020). The SPT-3G 2018 best-fit CMB power spectrum is indicated in gray. The ensemble of CMB data is visually consistent and yields a high signal-to-noise measurement of the power spectrum. (Figure 5 in Balkenhol et al. 2022)


Marginalized one- and two- dimensional posterior distributions for the SPT-3G 2018 TT/TE/EE data set (blue contours), Planck (black line contours), and ACT DR4 (gray contours) in Lambda-CDM. The constraints derived from SPT-3G data are in excellent agreement with the Planck constraints, including for H0. The SPT-3G and ACT data have similar constraining power and the differences in their constraints are compatible with statistical fluctuations. (Figure 7 in Balkenhol et al. 2022)


Ratio of the widths of marginalized posteriors from SPT-3G 2018 TT/TE/EE and TE/EE for select Lambda-CDM parameters (left half) and extension parameters (right half). The addition of TT data leads to improvements on core Lambda-CDM parameters between 8-27% and the H8 and sigma_8 posteriors tighten by 12% and 15%, respectively. For Lambda-CDM+A_L, Lambda-CDM+N_eff, and Lambda-CDM+N_eff+Y_P we report improvements for extension parameters between 5-24%. In the case of primordial magnetic fields, Lambda-CDM+b, TE/EE data alone suffers from a degeneracy between n_s and b and only the addition of TT data allows for a meaningful constraint. The vertical axis is split and the improvement on b shown only for visualization purposes. (Figure 9 in Balkenhol et al. 2022)


Compilation of H0 constraints from combinations of different CMB data sets: SPT-3G 2018, Planck (Planck results 2018 VI), WMAP (Bennett et al. 2013), ACT DR4 (Aiola et al. 2020). The vertical gray band indicates the 2 sigma constraint from the most precise supernovae and distance ladder analysis (Riess et al. 2022). SPT-3G 2018 data allow for a precision constraint on $H_0$ effectively independent from Planck data that deepens the Hubble tension. (Figure 10 in Balkenhol et al. 2022)


A compilation of S_8 constraints using different cosmological data sets: SPT-3G 2018, Planck (Planck results 2018 VI), WMAP (Bennett et al. 2013), DES Y3 (Abbott et al. 2022), DES Y3 + SPT (Abbott et al. 2022), and KiDS-1000 (Heymans et al. 2020). The central value of the SPT-3G constraint lies between those of low-redshift analyses and Planck. (Bottom panel of Figure 11 in Balkenhol et al. 2022)




We provide the foreground-subtracted minimum-variance combination of the SPT-3G 2018 multi-frequency band powers. The band powers cover the angular multipole range 750 < ell <= 3000 for TT and 300 < ell <= 3000 for TE and EE in bins of delta_ell = 50 for ell < 2000 and delta_ell = 100 for 2001 < ell. The band powers, band power errors (both in D_ell in units of uK^2), and associated band centers, are provided for plotting in a text file here. Each row is one ell-bin. The columns are (1) ell_min, (2) ell_max, (3) TT ell_center, (4) TT, (5) sigma_TT, (6) TE ell_center, (7) TE, (8) sigma_TE, (9) EE ell_center, (10) EE, (11) sigma_EE.

If you have any questions regarding this data set or its use, please contact Lennart Balkenhol (lennart_dot_balkenhol_at_iap_dot_fr).


Likelihood Code


We provide files in a zip archive here that can be added to the June 2021 version of CosmoMC to interface with the SPT-3G 2018 TT/TE/EE bandpowers discussed above. These files include the SPT-3G likelihood, SPT-3G data (multi-frequency bandpowers, covariance matrix, band power window functions, beam covariance, effective band centres, and calibration covariance), batch file, a sample .ini file, the baseline priors on foreground parameters, a proposal matrix for LCDM assuming the baseline priors, and a README with instructions for how to compile CosmoMC with the SPT-3G 2018 TT/TE/EE likelihood.

If you have any questions regarding the use of this likelihood, please contact Lennart Balkenhol (lennart_dot_balkenhol_at_iap_dot_fr).


Current (as of january 2023) likelihood version is v1.1 (solving an issue with ifort 2021 compiler), you can find below previous version of the likelihood package. Please use only use the latest version of the likelihood for production!

v1.0 (december 2022)


CosmoPower Models


The CosmoPower models used in the likelihood analysis are available on the CosmoPower github repository. The emulators have been trained on high-precision CAMB spectra and cover LCDM, LCDM+Neff, and LCDM+Alens models. More information is available on the CosmoPower github repository and in Section III A of Balkenhol et al. 2022. For additional information, please contact Lennart Balkenhol (lennart_dot_balkenhol_at_iap_dot_fr) or Alessio Spurio Mancini (a_dot_spuriomancini_at_ucl_dot_ac_dot_uk). If you use these emulators at any point in your work please cite Balkenhol et al. 2022 and the CosmoPower release paper.

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Last update:


September 7, 2011