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

DES Collaboration, SPT Collaboration, D. Thomas

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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 〈bh Pe 〉, using large-scale information. We find 〈bh Pe 〉 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 108.5 K but are incompatible with the model that assumes an AGN heating temperature of 108.0 K. These comparisons indicate that the data prefer a higher value of electron pressure than the simulations within r500c of the galaxies’ haloes.
Original languageEnglish
Pages (from-to)3163–3182
Number of pages20
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
Early online date20 Apr 2023
Publication statusPublished - 1 Jun 2023


  • UKRI
  • STFC
  • galaxies: structure
  • large scale structure of Universe
  • cosmology: observations

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