Joint tomographic measurement of thermal Sunyaev Zeldovich and the cosmic infrared background

Abstract

We present a novel method for the tomographic reconstruction of the bias-weighted mean electron pressure $\langle bP_e \rangle$ and star formation rate density $\langle bρ_{\mathrm{SFR}} \rangle$, by simultaneously modelling the contribution from the thermal Sunyaev-Zel'dovich (tSZ) effect and the Cosmic Infrared Background (CIB) to the cross-correlation between photometric galaxy samples and multi-frequency Cosmic Microwave Background (CMB) maps. The resulting measurements are independent of the galaxy clustering properties and robust against cross-contamination between tSZ and CIB. Applying this method to publicly available data, we reconstruct the cosmic evolution of $\langle bP_e \rangle$ and $\langle bρ_{\mathrm{SFR}} \rangle$ out to $z\sim1$, making our measurements publicly available. Our measurements of both quantities are broadly compatible with predictions from the fiducial FLAMINGO hydrodynamical simulation, although we observe a lower gas pressure at low redshifts, in agreement with other measurements.

Figures (9)

• Figure 1: Measurements of the galaxy-tSZ (top row) and galaxy-CIB (bottom row) angular power spectra for the lowest and highest redshift bins used in this analysis. This shows the spILC (or maximum-likelihood) estimates from galaxy-$T^\nu$ measurements. While we have a clear detection of both galaxy-tSZ and galaxy-CIB correlations for the fourth DESI LRG redshift bin, we measure a galaxy-CIB correlation consistent with zero from the WI$\times$SC sample.
• Figure 2: Joint tomographic measurements of bias-weighted electron pressure $\langle bP_e\rangle$ and bias-weighted star formation rate density $\langle b\rho_{\rm SFR} \rangle$ from direct correlation of WI$\times$SC and DESI LRG galaxy samples to multi-frequency observations from Planck. We compare to existing measurements 1909.091022006.146502206.15394 and to polynomial fits to measurements on FLAMINGO simulations studied in 2508.05319.
• Figure 3: $\langle bP_e\rangle$ and $\langle b\rho_{\rm SFR} \rangle$ measurements derived from different analysis settings. We included a comparison with ACT DR6 Compton-$y$ maps 2401.13033. Solid lines show $\langle bP_e\rangle$ and $\langle b\rho_{\rm SFR} \rangle$ measurements on the FLAMINGO simulation for its fiducial feedback model from 2508.05319.
• Figure 4: Power spectra measured for WI$\times$SC and DESI LRG auto-correlations (top row) and their correlation with Planck PR4 multi-frequency maps at 100, 143, 217, 353, 545 and 857 GHz. We only show data points with $\ell < k_{\rm max}\chi(\bar{z})$, and $k_{\rm max}<0.3~\rm Mpc$. For correlations involving Planck at 857 GHz, we apply an additional cut at $\ell=300$.
• Figure 5: Residual power spectrum vector normalized by the standard deviation. Each block, separated by dashed vertical lines, contains to all bandpowers (auto- and cross-correlations) involving one of the galaxy samples, which we indicate at the bottom of the plot. We show residuals for our fiducial analysis (dark blue) and when marginalising over CIB SEDs (blue). The latter case introduces 5 additional parameters (spectral tilt), improving the goodness-of-fit.