Regulation of Star Formation in the Molecular Gas Disks of Spiral Galaxies

Understanding the processes that regulate the formation of stars
within galaxies is one of the major themes in current astrophysical
research. Giant Molecular Clouds (GMCs, size ~ 40pc) are thought to
play a critical role in these processes as they host most of the
massive star formation occurring in our Galaxy. Detailed observations
on their scales can provide important insights on the properties of
the star forming interstellar medium and the conditions promoting the
formation of massive stars. Combining exquisite data on the molecular
gas disk in the grand-design spiral galaxy M51 at 40pc resolution from
the PdBI Arcsecond Whirlpool Survey (PAWS) with ancillary data across
the electromagnetic spectrum allowed us to investigate in detail how
molecular gas, dust and star formation relate across the galaxy disk
and test common assumption about Giant Molecular Clouds. I will
present highlights from our studies.