The properties of massive star forming regions
Event date
Wanggi Lim
N232 R103
Event Type

We have investigated the physical and kinematical properties of massive star forming regions at various evolutionary stages via near-infrared to centimeter observations. We first explore the initial conditions of the massive star formation by examining the properties of infrared dark clouds (IRDCs) and their natal Giant Molecular Clouds (GMCs). This study shows the observational evidences of grain growth for the first time in such extreme environments with the mid- to far-infrared data. We also show the potential importance of turbulence and magnetic field to form IRDCs. Secondly, we carry out a SOFIA-FORCAST 20 and 37μm imaging survey toward the GHII regions of Milky Way that are well known active massive star forming regions. In the study, we find a number of new massive young stellar objects where many of them are suggested to be at the earliest evolutionary stages. We discuss the global star forming histories of the GHII regions, by comparing a virial parameter, α, to L/M of proto-clusters. Finally, we analyze the kinematics of young stellar objects and molecular gases of the closest massive star forming cloud, Orion. We show a possibility of GMC-GMC collision as an important mechanism to form the Orion A cloud and stellar clusters in it.