The pressure profiles of hot gas in local galaxy groups
  Recent measurements of the Sunyaev-Zel'dovich (SZ) angular power spectrum
from the South Pole Telescope (SPT) and the Atacama Cosmology Telescope (ACT)
demonstrate the importance of understanding baryon physics when using the SZ
power spectrum to constrain cosmology. This is challenging since roughly half
of the SZ power at l=3000 is from low-mass systems with 10^13 h^-1 M_sun <
M_500 < 1.5x10^14 h^-1 M_sun, which are more difficult to study than systems of
higher mass. We present a study of the thermal pressure content for a sample of
local galaxy groups from Sun et al. (2009). The group Y_{sph, 500} - M_500
relation agrees with the one for clusters derived by Arnaud et al. (2010). The
group median pressure profile also agrees with the universal pressure profile
for clusters derived by Arnaud et al. (2010). With this in mind, we briefly
discuss several ways to alleviate the tension between the measured low SZ power
and the predictions from SZ templates.
