Molecular clouds in the LMC by NANTEN. II.

We have utilized the second catalog of 272 molecular clouds obtained by NANTEN (4m radio telescope of Nagoya University at Las Campanas Observatory, Chile) to compare the cloud distribution with signatures of massive star formation including stellar clusters, and optical and radio HII regions. We find that the molecular clouds are classified into three types according to the activities of massive star formation: Type I shows no signature of massive star formation; Type II is associated with relatively small HII region(s); and Type III with both HII region(s) and young stellar cluster(s).

The radio continuum sources were used to confirm that Type I giant molecular clouds (GMCs) do not host optically hidden HII regions. These signatures of massive star formation show a good spatial correlation with the molecular clouds in the sense that they are located within ~100pc of the molecular clouds.