The Resolved Kennicutt-Schmidt Law in Nearby Galaxies

The Kennicutt-Schmidt law (Schmidt 1959; Kennicutt 1998, hereafter K-S law) is a power law correlation between area averaged star formation rate (Σ_SFR) and gas surface density (Σ_gas). Despite its importance, the physics that underlie this correlation has remained unclear. The power law index, N, is a prime discriminator of the mechanisms that regulate star formation and form the K-S law (e.g. Leroy et al. 2008; Tan 2010). We present a study of the resolved K-S law for 10 nearby disk galaxies using our new CO(1-0) data at 750 and 500 pc resolutions. The CO(1-0) line emission is established as a tracer of the molecular gas column density, and results in a super-linear correlation (N = 1.3 and 1.8). We discuss the cause of the discrepancy between previous studies, and the mechanism of star formation indicated from our new results.