Friday, 27th May at 2.00pm @ the JAC

ABSTRACT: Both observations and theoretical perspectives show the importance of the dense molecular gas in galaxies, and that the active star formation is tightly related to the dense molecular gas. Our HCN survey, measure of the total amount of the dense molecular gas, in 65 galaxies has shown that there is a tight linear correlation between IR and HCN luminosities, whereas the correlation between IR and CO (measure of the total molecular gas) luminosities is nonlinear. Therefore, the global star formation rate (indicated by the IR luminosity) depends more intimately upon the amount of dense molecular gas traced by HCN than the total molecular gas measured by CO. And the global Schmidt law of star formation in terms of dense molecular gas appears to be linear in all star-forming galaxies. This linear relationship appears to extend to the active star-forming giant molecular cloud cores as well.