Globular Clusters Formed within Dark Halos I: present-day abundance,
  distribution and kinematics
  We explore a scenario where metal poor globular clusters (GCs) form at the
centres of their own dark matter halos in the early universe before
reionization. This hypothesis leads to predictions about the abundance,
distribution and kinematics of GCs today that we explore using cosmological
N-body simulations and analytical modelling. We find that selecting the massive
tail of collapsed objects at $z\gtrsim 9$ as GC formation sites leads to four
main predictions: i) a highly clustered population of GCs around galaxies
today, ii) a natural scaling between number of GCs and halo virial mass that
follows roughly the observed trend, iii) a very low number of free floating GCs
outside massive halos and iv) GCs should be embedded within massive and
extended dark matter (sub)halos. We find that the strongest constraint to the
model is given by the combination of (i) and (ii): a mass cut to tagged GCs
halos which accounts for the number density of metal poor GCs today predicts a
radial distribution that is too extended compared to recent observations. On
the other hand, a mass cut sufficient to match the observed half number radius
could only explain 60% of the metal poor population. In all cases, observations
favour early redshifts for GC formation ($z\geq 15$).
