Measurement of the Splashback Feature around SZ-selected Galaxy Clusters
  with DES, SPT and ACT
  We present a detection of the splashback feature around galaxy clusters
selected using their Sunyaev-Zel'dovich (SZ) signal. Recent measurements of the
splashback feature around optically selected galaxy clusters have found that
the splashback radius, $r_{\rm sp}$, is smaller than predicted by N-body
simulations. A possible explanation for this discrepancy is that $r_{\rm sp}$
inferred from the observed radial distribution of galaxies is affected by
selection effects related to the optical cluster-finding algorithms. We test
this possibility by measuring the splashback feature in clusters selected via
the SZ effect in data from the South Pole Telescope SZ survey and the Atacama
Cosmology Telescope Polarimeter survey. The measurement is accomplished by
correlating these clusters with galaxies detected in the Dark Energy Survey
Year 3 data. The SZ observable used to select clusters in this analysis is
expected to have a tighter correlation with halo mass and to be more immune to
projection effects and aperture-induced biases than optically selected
clusters. We find that the measured $r_{\rm sp}$ for SZ-selected clusters is
consistent with the expectations from simulations, although the small number of
SZ-selected clusters makes a precise comparison difficult. In agreement with
previous work, when using optically selected redMaPPer clusters, $r_{\rm sp}$
is $\sim$ $2\sigma$ smaller than in the simulations. These results motivate
detailed investigations of selection biases in optically selected cluster
catalogs and exploration of the splashback feature around larger samples of
SZ-selected clusters. Additionally, we investigate trends in the galaxy profile
and splashback feature as a function of galaxy color, finding that blue
galaxies have profiles close to a power law with no discernible splashback
feature, which is consistent with them being on their first infall into the
cluster.
