  A matched filter technique is applied to the Planck all-sky Compton
y-parameter map to measure the thermal Sunyaev-Zel'dovich (tSZ) effect produced
by galaxy groups of different halo masses selected from large redshift surveys
in the low-z Universe. Reliable halo mass estimates are available for all the
groups, which allows us to bin groups of similar halo masses to investigate how
the tSZ effect depends on halo mass over a large mass range. Filters are
simultaneously matched for all groups to minimize projection effects. We find
that the integrated y-parameter and the hot gas content it implies are
consistent with the predictions of the universal pressure profile model only
for massive groups above $10^{14}\,{\rm M}_\odot$, but much lower than the
model prediction for low-mass groups. The halo mass dependence found is in good
agreement with the predictions of a set of simulations that include strong AGN
feedback, but simulations including only supernova feedback significantly over
predict the hot gas contents in galaxy groups. Our results suggest that hot gas
in galaxy groups is either effectively ejected or in phases much below the
virial temperatures of the host halos.
