The GOGREEN survey: the internal dynamics of clusters of galaxies at
  redshift 0.9-1.4
  We aim to determine the mass, velocity anisotropy, and pseudo phase-space
density profiles (M(r), beta(r), and Q(r), respectively) of clusters of
galaxies at the highest redshifts investigated in detail so far. We combine the
GOGREEN and GCLASS spectroscopic data-sets for 14 clusters with mass M200 >
10^14 Msolar at redshifts 0.9 < z < 1.4. We stack these 14 clusters into an
ensemble cluster of 581 member galaxies with stellar mass > 10^9.5 M_solar. We
use the MAMPOSSt method and the inversion of the Jeans equation technique to
determine M(r) and beta(r). We then combine the results of the M(r) and beta(r)
analysis to determine Q(r) for the ensemble cluster. The concentration c200 of
the ensemble cluster M(r) is in excellent agreement with predictions from
LambdaCDM cosmological numerical simulations, and with previous determinations
for clusters of similar mass and at similar redshifts, obtained from
gravitational lensing and X-ray data. We see no significant difference between
the total mass density and either the galaxy number density distributions or
the stellar mass distribution. Star-forming galaxies are spatially
significantly less concentrated than quiescent galaxies. The orbits of cluster
galaxies are isotropic near the center and more radial outside. Star-forming
galaxies and galaxies of low stellar mass tend to move on more radially
elongated orbits than quiescent galaxies and galaxies of high stellar mass.
Q(r), determined either using the total mass or the number density profile, is
very close to the power-law behavior predicted by numerical simulations. The
internal dynamics of clusters at the highest redshift probed in detail so far
are very similar to those of lower-redshift clusters, and in excellent
agreement with predictions of numerical simulations. The clusters in our sample
have already reached a high degree of dynamical relaxation. (Abridged)
