Detection of Thermal Sunyaev–Zel’dovich Effect in the Circumgalactic Medium of Low-mass Galaxies—A Surprising Pattern in Self-similarity and Baryon Sufficiency

Abstract We report on the measurement of thermal Sunyaev–Zel’dovich (tSZ) effect in circumgalactic medium (CGM) 641,923 galaxies with M ⋆ = 10 9.8–11.3 ⊙ at z < 0.5, pushing exploration tSZ to lower-mass compared those previous studies. cross-correlate galaxy catalog Wide-field Infrared Survey Explorer and SuperCOSMOS Compton- y maps derived from combined data Atacama Cosmology Telescope Planck. improve analysis methods (correcting for cosmic infrared background Galactic dust, masking clusters radio sources, stacking, employing aperture photometry), as well modeling (taking into account beam smearing, “two-halo” term, any zero-point offset). constrain pressure CGM 10.6–11.3 a generalized Navarro–Frenk–White profile provide upper limits 9.8–10.6 galaxies. The relation between 500 (obtained an empirical – 200 concentration factor) Y ˜ R 500 sph (a measure energy within R ) is >2 σ steeper than self-similarity deviation same that has been reported previously higher-mass halos. calculate baryon fraction galaxies, f b , assuming be virial temperature . exhibits nonmonotonic trend mass, 10.9–11.2 being baryon-sufficient.