MR. JONATHAN FREUNDLICH

Massive galaxies in the distant Universe form stars at much higher rates than today. Was star formation qualitatively different at high redshift? Although direct resolution of the star forming regions of high redshift galaxies is still challenging, molecular gas observations at the IRAM Plateau de Bure interferometer (Tacconi, Combes & IRAM Large Program Consortium) enable us to study the star formation efficiency at sub-galactic scales around redshift z = 1.2, and thus to help characterize the star formation processes at this epoch. We present a method to obtain the gas and star formation rate (SFR) surface densities of ensembles of clumps composing galaxies at this redshift, based on the identification of these structures in position-velocity diagrams corresponding to slices within the galaxies, and derive a spatially resolved Kennicutt-Schmidt (KS) relation at a scale of about 8 kpc. The data globally indicates an average depletion time of 1.9 Gyr, but with significant variations from point to point within the galaxies.