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

• Published in: Monthly Notices of the Royal Astronomical Society
• Main Author: Desai, Shantanu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2023
• Subjects: Physics; Astronomy Astrophysics; South Pole; South pole
• Online Access: http://raiith.iith.ac.in/11775/; https://doi.org/10.1093/mnras/stad1167; http://raiith.iith.ac.in/11775/1/stad1167.pdf

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+−000403, 0.28+−000504, 0.45+−001006, 0.54+−000708, 0.61+−000608, 0.63+−000807] 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.