Indications of a sub-linear and non-universal Kennicutt-Schmidt relationship

Understand

We estimate the parameters of the Kennicutt-Schmidt (KS) relationship, linking the star formation rate (Sigma_SFR) to the molecular gas surface density (Sigma_mol), in the STING sample of nearby disk galaxies using a hierarchical Bayesian method.

• This method rigorously treats measurement uncertainties, and provides accurate parameter estimates for both individual galaxies and the entire population.
• Assuming standard conversion factors to estimate Sigma_SFR and Sigma_mol from the observations, we find that the KS parameters vary between galaxies, indicating that no universal relationship holds for all galaxies.
• The KS slope of the whole population is 0.76, with the 2sigma range extending from 0.58 to 0.94.