The Spitzer South Pole Telescope Deep Field Survey: Linking galaxies and
  halos at z=1.5
  We present an analysis of the clustering of high-redshift galaxies in the
recently completed 94 deg$^2$ Spitzer-SPT Deep Field survey. Applying flux and
color cuts to the mid-infrared photometry efficiently selects galaxies at
$z\sim1.5$ in the stellar mass range $10^{10}-10^{11}M_\odot$, making this
sample the largest used so far to study such a distant population. We measure
the angular correlation function in different flux-limited samples at scales
$>6^{\prime \prime}$ (corresponding to physical distances $>0.05$ Mpc) and
thereby map the one- and two-halo contributions to the clustering. We fit halo
occupation distributions and determine how the central galaxy's stellar mass
and satellite occupation depend on the halo mass. We measure a prominent peak
in the stellar-to-halo mass ratio at a halo mass of $\log(M_{\rm halo} /
M_\odot) = 12.44\pm0.08$, 4.5 times higher than the $z=0$ value. This supports
the idea of an evolving mass threshold above which star formation is quenched.
We estimate the large-scale bias in the range $b_g=2-4$ and the satellite
fraction to be $f_\mathrm{sat}\sim0.2$, showing a clear evolution compared to
$z=0$. We also find that, above a given stellar mass limit, the fraction of
galaxies that are in similar mass pairs is higher at $z=1.5$ than at $z=0$. In
addition, we measure that this fraction mildly increases with the stellar mass
limit at $z=1.5$, which is the opposite of the behavior seen at low-redshift.
