Probing Hot Gas Components of Circumgalactic Medium in Cosmological
  Simulations with the Thermal Sunyaev-Zel'dovich Effect
  The thermal Sunyaev-Zel'dovich (tSZ) effect is a powerful tool with the
potential for constraining directly the properties of the hot gas that
dominates dark matter halos because it measures pressure and thus thermal
energy density. Studying this hot component of the circumgalactic medium (CGM)
is important because it is strongly impacted by star-formation and active
galactic nuclei (AGN) activity in galaxies, participating in the feedback loop
that regulates star and black hole mass growth in galaxies.
  We study the tSZ effect across a wide halo mass range using three
cosmological hydrodynamical simulations: Illustris-TNG, EAGLE, and FIRE-2.
Specifically, we present the scaling relation between tSZ signal and halo mass
and radial profiles of gas density, temperature, and pressure for all three
simulations. The analysis includes comparisons to Planck tSZ observations and
to the thermal pressure profile inferred from the Atacama Cosmology Telescope
(ACT) measurements. We compare these tSZ data to the simulations to interpret
the measurements in terms of feedback and accretion processes in the CGM. We
also identify as-yet unobserved potential signatures of these processes that
may be visible in future measurements, which will have the capability of
measuring tSZ signals to even lower masses. We also perform internal
comparisons between runs with different physical assumptions. We conclude: (1)
there is strong evidence for the impact of feedback at $R_{500}$ but that this
impact decreases by $5R_{500}$, and (2) the thermodynamic profiles of the CGM
are highly dependent on the implemented model, such as cosmic-ray or AGN
feedback prescriptions.
