Giant Molecular Clouds and On-Going Star Formation in the LMC and SMC

After completion of the first CO survey of the Large Magellanic Cloud with NANTEN, we are continuing more sensitive CO survey of the both Large and Small Magellanic Clouds. These will help us to obtain a new insight into formation of GMCs and clusters. The new NANTEN results have reinforced our conclusion that the youngest stellar clusters and H II regions show good spatial correlation with GMCs, and that SNRs are only poorly correlated with CO emission. This support the view that cluster formation is very rapid, in a few Myr, and that the GMCs are quickly dissipated by the UV photons from the clusters. In addition, the novel aspects of this study include the identification of starless GMCs, apparently very rare in the Galaxy.