Physics of a clumpy lensed galaxy at z=1.6
  Observations have shown that massive star-forming clumps are present in the
internal structure of high-redshift galaxies. One way to study these clumps in
detail with a higher spatial resolution is by exploiting the power of strong
gravitational lensing which stretches images on the sky. In this work, we
present an analysis of the clumpy galaxy A68-HLS115 at $z=1.5858$, located
behind the cluster Abell 68, but strongly lensed by a cluster galaxy member.
Resolved observations with SINFONI/VLT in the near-infrared show Ha, Hb, [NII],
and [OIII] emission lines. Combined with images covering the B band to the
far-infrared and CO(2-1) observations, this makes this galaxy one of the only
sources for which such multi-band observations are available and for which it
is possible to study the properties of resolved star-forming clumps and to
perform a detailed analysis of the integrated properties, kinematics, and
metallicity. We obtain a stability of $\upsilon_{rot}/\sigma_0 = 2.73$ by
modeling the kinematics, which means that the galaxy is dominated by rotation,
but this ratio also indicates that the disk is marginally stable. We find a
high intrinsic velocity dispersion of $80\pm10$ km s$^{-1}$ that could be
explained by the high gas fraction of $f_{gas}=0.75\pm0.15$ observed in this
galaxy. This high $f_{gas}$ and the observed sSFR of $\rm 3.12 \, Gyr^{-1}$
suggest that the disk turbulence and instabilities are mostly regulated by
incoming gas. The direct measure of the Toomre stability criterion of
$Q_{crit}=0.70$ could also indicate the presence of a quasi-stable thick disk.
Finally, we identify three clumps in the Ha map which have similar velocity
dispersions, metallicities, and seem to be embedded in the rotating disk. These
three clumps contribute together to $40\%$ on the SFR(Ha) of the galaxy and
show a SFR density about $100$ times higher than HII regions in the local
Universe.
