  Recent advances in cosmological observations have provided an unprecedented
opportunity to investigate the distribution of baryons relative to the
underlying matter. In this work, we robustly show that the gas is much more
extended than the dark matter at 40$\sigma$ and the amount of baryonic feedback
at $z \lesssim 1$ strongly disfavors low-feedback models such as that of
state-of-the-art hydrodynamical simulation IllustrisTNG compared with
high-feedback models such as that of the original Illustris simulation. This
has important implications for bridging the gap between theory and observations
and understanding galaxy formation and evolution. Furthermore, a better grasp
of the baryon-dark matter link is critical to future cosmological analyses,
which are currently impeded by our limited knowledge of baryonic feedback.
Here, we measure the kinematic Sunyaev-Zel'dovich (kSZ) effect from the Atacama
Cosmology Telescope (ACT), stacked on the luminous red galaxy (LRG) sample of
the Dark Energy Spectroscopic Instrument (DESI) imaging survey. This is the
first analysis to use photometric redshifts for reconstructing galaxy
velocities. Due to the large number of galaxies comprising the DESI imaging
survey, this is the highest signal-to-noise stacked kSZ measurement to date: we
detect the signal at 13$\sigma$ and find that the gas is more spread out than
the dark matter at $\sim$40$\sigma$. Our work opens up the possibility to
recalibrate large hydrodynamical simulations using the kSZ effect. In addition,
our findings point towards a way of alleviating inconsistencies between weak
lensing surveys and cosmic microwave background (CMB) experiments such as the
`low $S_8$' tension, and shed light on long-standing enigmas in astrophysics
such as the `missing baryon' problem.
