The SINS survey of z~2 galaxy kinematics: properties of the giant star
  forming clumps
  We have studied the properties of giant star forming clumps in five z~2
star-forming disks with deep SINFONI AO spectroscopy at the ESO VLT. The clumps
reside in disk regions where the Toomre Q-parameter is below unity, consistent
with their being bound and having formed from gravitational instability. Broad
H{\alpha}/[NII] line wings demonstrate that the clumps are launching sites of
powerful outflows. The inferred outflow rates are comparable to or exceed the
star formation rates, in one case by a factor of eight. Typical clumps may lose
a fraction of their original gas by feedback in a few hundred million years,
allowing them to migrate into the center. The most active clumps may lose much
of their mass and disrupt in the disk. The clumps leave a modest imprint on the
gas kinematics. Velocity gradients across the clumps are 10-40 km/s/kpc,
similar to the galactic rotation gradients. Given beam smearing and clump
sizes, these gradients may be consistent with significant rotational support in
typical clumps. Extreme clumps may not be rotationally supported; either they
are not virialized, or they are predominantly pressure supported. The velocity
dispersion is spatially rather constant and increases only weakly with star
formation surface density. The large velocity dispersions may be driven by the
release of gravitational energy, either at the outer disk/accreting streams
interface, and/or by the clump migration within the disk. Spatial variations in
the inferred gas phase oxygen abundance are broadly consistent with inside-out
growing disks, and/or with inward migration of the clumps.
