The Global Star Formation Law: from Dense Cores to Extreme Starbursts at High-z

Active star formation is tightly related to the dense molecular gas in the giant molecular cloud dense cores. HCN (measure of the dense molecular gas) survey of 65 galaxies (including 10 ultraluminous galaxies) reveals a tight linear correlation between HCN and IR (star formation rate) luminosities, whereas the correlation between IR and CO (measure of the total molecular gas) luminosities is nonlinear. This suggests that the global star formation rate depends more intimately upon the amount of dense molecular gas than the total molecular gas content. This linear relationship appears to extend to both the star-forming dense cores in the Galaxy and the hyperluminous extreme starbursts at high redshift, and the resolved measurements in nearby star-forming galaxies can bridge the dense cores with the distant galaxies. Therefore, the global Schmidt law of star formation appears to be linear all the way from dense cores to extreme starbursts in distant Universe spanning over nine orders of magnitude in IR luminosity.

 

Fecha: 
26/06/2006 - 20:00
Conferenciante: 
Yu Gao
Filiación: 
Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing (China)


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