Multiply lensed star forming clumps in the A521-sys1 galaxy at redshift 1

We study the population of star-forming clumps in A521-sys1, a $\rm z=1.04$ system gravitationally lensed by the foreground ($\rm z=0.25$) cluster Abell 0521. The galaxy presents one complete counter--image with a mean magnification of $\rm μ\sim4$ and a wide arc containing two partial images of A521-sys1 with magnifications reaching $\rm μ>20$, allowing the investigations of clumps down to scales of $\rm R_{eff}