  The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a drift-scan
interferometer designed to map the entire northern sky every 24 hours. The
all-sky coverage and sensitivity to neutral hydrogen flux at intermediate
redshifts makes the instrument a resource for other exciting science in
addition to cosmology for which it was originally designed. Characterizing the
contents of CHIME's beam-smoothed maps will aid in planning novel use-cases for
the instrument, particularly those pertaining to galaxy evolution studies.
Here, we demonstrate its utility for the study of the HI content of stacked
galaxy populations across environments. Focusing first on galaxy clusters, we
use simulated data from the IllustrisTNG project to understand the relative
contribution of objects that fall into CHIME's synthesized beam to the observed
HI flux using stacking analyses at a couple of representative redshifts. We
find that there is an appreciable difference in the estimated stacked flux when
galaxy clusters or cluster member galaxies are used as tracers compared to
stacking on a general galaxy catalog. Stacking on galaxy clusters, we report
that it is possible to recover an average $M_\mathrm{HI}$ for clusters as a
function of redshift and selection criteria.
