Investigating the Formation of Small Protostellar Clusters

恒星诞生于寒冷、致密的气体和尘埃凝聚体中，称为致密核心，而致密核心通常形成于更大的星协或星团中。尽管大多数恒星，包括我们的太阳，都是在星团中形成的，但我们对这种形成模式的了解要比孤立形成的恒星少得多，这是因为所需的观测更具挑战性。了解恒星如何形成星团会影响各种科学问题，包括像我们这样的太阳系是否能够形成。随着新的望远镜，如阿塔卡马大型毫米阵列（阿尔马）和詹姆斯韦伯太空望远镜（JWST）的上线，并提供壮观的新观点的恒星形成集群，是时候在这一领域进行详细的研究。 我的研究项目集中在测量集群形成的初始条件以及集群成员如何形成和获得质量。为了准备我的NSERC基金，我正在开发一个新颖的星团目录，在它们开始诞生恒星之前就被捕获了。这些密集的核心集群是使用詹姆斯克拉克麦克斯韦望远镜的古尔德带调查，这项工作的首要调查确定的。这个非常年轻和邻近的星团的独特样本构成了我的团队对星团形成进行更广泛研究的起点。我的建议的第一个方面是描述与形成星系团有关的气体运动的特征。最近完成的绿色银行氨调查（GAS）将提供观测结果，该调查是对天空大面积稠密气体运动的第一次详细测量。结合GAS和GBS数据将使我的团队能够充分表征这些年轻的星团形成系统的特性。该提案的第二个方面是测试一种流行的集群形成模型，其中，非结构性结构负责提供形成集群成员所需的大部分材料。 利用GBS和GAS数据集以及沿着一些额外的观测结果，将有可能对这一模型进行系统的验证。这项分析将是第一次围绕如此年轻和小的星系团进行的此类分析。我建议的第三个方面通过以更高的角分辨率深入研究星团形成区域来增强前两个方面。将使用Jansky甚大阵列和阿尔马测量一个子集的集群形成系统的细尺度细节。这些观测将揭示结构中的特征，这些特征反映了集群环境难以测量的特性。例如，致密核心内部的子结构水平（平滑与多峰）反映了存在多少湍流运动以及核心如何能够获得质量。通过这三个方面的综合结果，将更好地理解小的致密核心团簇的形成和演化。研究结果还将指导未来对更大、更复杂的星团系统的分析，大多数恒星都是在这些星团系统中形成的。

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.