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

Abstract

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 {\it Planck} mission. We model this cross-correlation measurement together with the galaxy auto-correlation 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 $[0.16_{-0.04}^{+0.03},0.28_{-0.05}^{+0.04},0.45_{-0.10}^{+0.06},0.54_{-0.07}^{+0.08},0.61_{-0.06}^{+0.08},0.63_{-0.08}^{+0.07}]$ meV cm${}^{-3}$ at redshifts $z\sim [0.30,0.46,0.62,0.77,0.89,0.97]$. 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' halos.

20 pages, 9 figures. Submitted to MNRAS