Towards sub-kpc scale kinematics of molecular and ionized gas of
  star-forming galaxies at $z\sim1$
  We compare the molecular and ionized gas kinematics of two strongly lensed
galaxies at $z\sim1$ based on observations from ALMA and MUSE. We derive the CO
and [OII] rotation curves and dispersion profiles of these two galaxies. We
find a difference between the observed molecular and ionized gas rotation
curves for one of the galaxies, the Cosmic Snake, for which we obtain a spatial
resolution of few hundred parsecs along the major axis. The rotation curve of
the molecular gas is steeper than the rotation curve of the ionized gas. In the
second galaxy, A521, the molecular and ionized gas rotation curves are
consistent, but the spatial resolution is only of few kpc on the major axis.
Using simulations, we investigate the effect of the thickness of the gas disk
and effective radius on the observed rotation curves and find that a more
extended and thicker disk smooths the curve. We also find that the presence of
a strongly inclined thick disk (>1 kpc) can smooth the rotation curve because
it degrades the spatial resolution along the line of sight. By building a model
using a stellar disk and two gas disks, we reproduce the rotation curves of the
Cosmic Snake with a molecular gas disk that is more massive and more radially
and vertically concentrated than the ionized gas disk. Finally, we also obtain
an intrinsic velocity dispersion in the Cosmic Snake of 18.5+-7 km/s and
19.5+-6 km/s for the molecular and ionized gas, respectively, which is
consistent with a molecular disk with a smaller and thinner disk. For A521, the
intrinsic velocity dispersion values are 11+-8 km/s and 54+-11 km/s, with a
higher value for the ionized gas. This could indicate that the ionized gas disk
is thicker and more turbulent in this galaxy. These results highlight the
different spatial distribution of the molecular and ionized gas disks at
$z\sim1$ and suggest the presence of thick ionized gas disks at this epoch.
