Mapping gas around massive galaxies: cross-correlation of DES Y3 galaxies and Compton-y maps from SPT and Planck

We cross-correlate positions of galaxies measured in data from the first three years of the Dark Energy Survey with Compton-y maps generated using data from the South Pole Telescope (SPT) and the Planck mission. We model this cross-correlation measurement together with the galaxy autocorrelation to constrain the distribution of gas in the Universe. We measure the hydrostatic mass bias or, equivalently, the mean halo bias-weighted electron pressure 〈b_h P_e 〉, using large-scale information. We find 〈b_h P_e 〉 to be [0.16+0.03−0.04,0.28+0.04−0.05,0.45+0.06−0.10,0.54+0.08−0.07,0.61+0.08−0.06,0.63+0.07−0.08] meV cm⁻³ at redshifts z ∼ [0.30, 0.46, 0.62, 0.77, 0.89, 0.97]. These values are consistent with previous work where measurements exist in the redshift range. We also constrain the mean gas profile using small-scale information, enabled by the high-resolution of the SPT data. We compare our measurements to different parametrized profiles based on the cosmo-OWLS hydrodynamical simulations. We find that our data are consistent with the simulation that assumes an AGN heating temperature of 10^8.5 K but are incompatible with the model that assumes an AGN heating temperature of 10^8.0 K. These comparisons indicate that the data prefer a higher value of electron pressure than the simulations within r_500c of the galaxies’ haloes.