  The nearby, almost face-on, and interacting galaxy M51 offers an excellent
opportunity to study the distribution of molecular gas and the mechanisms
governing the star formation rate. We have created a complete map of M51 in
12CO 2-1 at a resolution of 11 arcsec corresponding to 450 kpc using HERA at
the IRAM-30m telescope. In Schuster et al. (2006) we have combined these data
with maps of HI and the radio-continuum to study the star formation efficiency,
the local Schmidt law, and Toomre stability of the disk in radial averages out
to radii of 12 kpc. Here, we also discuss the distribution of giant molecular
associations and its mass spectrum, in comparison with similar studies in the
literature.
