The Birth and Death of Stellar Clusters: Uncloaking the Roles of Stars, Gas, and Physical Environment in Nearby Galaxies

更好地了解星团从诞生到死亡的整个生命周期，对于天文学的许多领域都很重要，包括星系的形成和演化、初始恒星质量函数、星团中形成的恒星的比例，以及理解现在古老的球状星团年轻时早期宇宙中恒星形成的条件是否与今天相同。这个项目的目标是阐明一个星团生命周期中的两个尚不为人所知的时代--就在它们诞生之前和形成后不久。这个项目支持博士后研究人员的培训。为该项目所做的研究成果将被用于与年龄相适应的动手活动，作为旨在培养中学女生对科学的兴趣的全天外展活动的一部分。研究人员将研究附近星系中星团的形成及其破坏。星团形成是星系中最基本的过程之一，它发生在极其多样化的环境和物理条件下，比仅在银河系中发现的要广泛得多。星系团诞生在巨大的分子气云的致密部分，许多星团随后被几个不同的物理过程分散。这个项目的目标是阐明一个星团生命周期中的两个尚不为人所知的时代--就在它们诞生之前和它们形成后不久。通过国家科学基金会新的阿塔卡马大型毫米波阵列的观测，可以直接研究遥远星系中的云层，覆盖的物理条件比我们最近的星系要大得多。这些星云的性质，特别是它们的质量函数，当与同一星系中年轻星团的性质相比较时，为理解恒星和星团在不同物理条件下形成的效率提供了重要线索。即使在分子云中形成星团时，新生的大质量恒星注入的能量和动量也会推出剩余的星际物质，最终关闭恒星的形成，使许多年轻的星团不受引力约束。这一过程的物理约束很差，但通过新启用的探索频道望远镜(DCT)对非常年轻的星系团内部和外部的电离气体进行测量，将区分不同的预测。

A better understanding of the full life cycle of star clusters, from birth to death, is important for many areas of astronomy, including the formation and evolution of galaxies, the initial stellar mass function, the fraction of stars forming in clusters, and for understanding whether the conditions for star formation in the early universe when now-ancient globular clusters were young are the same as they are today. The goal of this program is to shed light on two as-yet poorly understood epochs in the life cycle of a star cluster -- just before they are born and very soon after they form.This program supports the training of a postdoctoral researcher. Results from the research done for this project will be used in age-appropriate, hands-on, activities as part of 'Girls in Science', an all-day outreach event aimed to foster middle-school girls' interest in science. The investigators will study the formation of star clusters, and also their destruction, in nearby galaxies. Star cluster formation is one of the most fundamental processes in galaxies, and occurs over an incredibly diverse range of environments and physical conditions, far broader than those found in the Milky Way alone. Clusters are born in the dense parts of giant clouds of molecular gas, and many are subsequently dispersed by several different physical processes. The goal of this program is to shed light on two as-yet poorly understood epochs in the life cycle of a star cluster -- just before they are born and very soon after they form. Observations with the National Science Foundation's new Atacama Large Millimeter Array enable direct study of clouds in distant galaxies covering a much wider range of physical conditions than our nearest neighbors. The properties of these clouds, particularly their mass functions, when compared with those of young star clusters in the same galaxy, provide important clues to understand the efficiency with which stars and clusters form under different physical conditions. Even as clusters are forming within molecular clouds, the energy and momentum injected by newly born massive stars pushes out left-over interstellar material, which eventually shuts off star formation and leaves many young clusters gravitationally unbound. Physical constraints on this process are poor, but measurements of the ionized gas both inside and outside of very young clusters using observations with the newly commissioned Discovery Channel Telescope (DCT) will distinguish between different predictions.