2 SAMPLE SELECTION

3 ESTIMATING THE MOLECULAR GAS SURFACE DENSITY (  $\Sigma_{\mathrm{gas}}$  )

4 RESULTS

5 COMPARISON TO PREVIOUS Σ SFR VERSUS  $\Sigma_{\mathrm{gas}}$ RELATIONS

6 COMPARING $\Sigma_{\mathrm{gas}}$ PREDICTIONS BY INVERTING STAR FORMATION LAWS

7 CONCLUSIONS