Investigating the Formation of Small Protostellar Clusters

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Stars are born within cold, dense condensations of gas and dust, known as dense cores, which in turn usually form within larger associations or clusters. Despite most stars, including our Sun, having formed in clusters, we know much less about this formation mode than stars forming in isolation, due to the more challenging nature of the observations required. Understanding how stars form in clusters impacts a variety of science questions, including whether solar systems like our own would be able to form. With new telescopes such as the Atacama Large Millimetre Array (ALMA) and the James Webb Space Telescope (JWST) coming online and offering spectacular new views on star-forming clusters, the time is right to pursue a detailed study in this area. ******My research program centres on measuring the initial conditions for cluster formation and how cluster members form and gain mass. In preparation for my NSERC grant, I am developing a novel catalogue of clusters caught before they begin birthing stars. These clusters of dense cores are identified using the James Clerk Maxwell Telescope's Gould Belt Survey, the premier survey for this work. This unique sample of very young and nearby clusters forms the launching point of my group's broader investigation into cluster formation.******The first prong of my proposal is to characterize the motions of the gas associated with forming clusters. Observations will be provided by the recently completed Green Bank Ammonia Survey (GAS), which is providing one of the first detailed measurements of dense gas motion across large areas of the sky. Combining the GAS and GBS data will allow my group to fully characterize the properties of these young cluster-forming systems.******The second prong of the proposal is to test a popular model of cluster formation wherein filamentary structures are responsible for supplying most of the material needed to form the cluster members. Systematic verification of this model will be possible, using a combination of the GBS and GAS datasets, along with some additional observations. This analysis will be the first of its kind around such young and small clusters.******The third prong of my proposal augments the first two prongs by delving into the cluster-forming regions at higher angular resolution. The fine scale details of a subset of the cluster forming systems will be measured using the Jansky Very Large Array and ALMA. These observations will reveal features in the structures that reflect difficult to measure properties of the cluster environment. For example, the level of substructure within a dense core (smooth versus multi-peaked) reflects how much turbulent motion is present and how the core is able to gain mass.******Through the combined results of these three prongs, the formation and evolution of small dense core clusters will be better understood. The results will additionally guide future analyses of larger and more complex clustered systems, within which the majority of stars formed.**