Towards a global understanding of high mass star formation

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Over the past 20 years there have been significant advances in the field of star formation. We have determined that all stars are born deeply embedded and emerge over time as the surrounding material is either accreted or dispersed. We have discovered InfraRed Dark Clouds which are cold, dense clouds of gas and dust seen in silhouette against the bright mid-infrared background produced by the Galactic Plane and learned that they are likely the progenitors of young stars, including stars more massive than the Sun. We have also learned that the chemical composition of the gas in a star forming region can have an effect on its physical evolution. A large part of our progress in the field of star formation has focused solely on the formation of low-mass stars, predominantly because these objects form isolated from other nearby stars, reducing confusion. However, it has now been recognized that most stars, and especially stars more massive than the Sun, do not form in an isolated fashion. Instead, over approximately 90% of all stars form in clusters, in regions which are also forming massive stars. Similar progress in our understanding of the formation of massive stars has been hampered by several factors: a) The greater distances of the Giant Molecular Clouds that are the birth sites of massive stars makes studies of individual objects difficult. b) Contraction timescales for massive stars are much shorter meaning that examples of the earliest phases are rare. c) The very nature of clustered star formation increases the chances for confusion. As a result, even though massive stars are key drivers of energy production and heavy element abundance in the Galaxy, their formation mechanism is unclear. In this proposal, funding is requested to tackle some of the most pressing issues in the field of massive star formation. What are the properties (physical & velocity structure, density, temperature, chemical abundances, etc.) of massive star forming regions? What makes them different from regions forming low mass stars? How do the clouds that give birth to massive stars form in the first place?