Science Support for the SCUBA-2 and Herschel Galactic Plane Surveys: Triggered Star Formation in the Galaxy

对星际介质中如何触发或诱导恒星形成的定量理解是整个天体物理学的基础，但目前还没有实现。正是这种恒星形成的模式导致了在早期宇宙中观测到的强烈的恒星爆发。为了获得这种理解，我们需要测量恒星从星系分子气体云形成的效率，以及形成的新恒星的质量分布，如何随着影响云的物理力量的强度而变化，比如风和与热恒星相关的电离区域的扩张，以及超新星爆炸。我们还需要了解恒星形成的初始条件：云本身的起源，它们特有的湍流，以及这些条件的差异如何影响自发的恒星形成。我们在这个方向上取得了重大进展，对单星系、恒星形成、巨大分子云的恒星形成内容进行了全面的观测研究。现在的进展需要从具有不同初始和环境条件的类似地区获得大量样本。申请人正在领导一个国际项目，使用新的、stfc资助的、最先进的仪器在夏威夷的詹姆斯·克拉克·麦克斯韦望远镜上调查银河系的平面。这项调查将对银河系大部分地区的所有大质量恒星形成进行普查，这将导致该领域的重大进展。它将首次允许研究具有各种内部和外部物理环境的恒星形成区域的代表性样本。申请人也是一个国际联盟的重要活跃成员，该联盟已经获得了300多个小时的赫歇尔远红外空间天文台的观测时间，以调查内银河面。该项目将提供重要的光度和温度数据（因此演化状态），除了SCUBA-2在银河系内区域探测到的最冷光源。本研究将揭示初始条件、外部环境和反馈对恒星形成效率和结构质量函数的定量影响。这些结果将推动我们对恒星形成的理解，并为其他领域提供有价值的输入，例如星系的形成和演化研究。

A quantitative understanding of how star formation is triggered or induced in the interstellar medium is fundamental to the whole of Astrophysics but is not yet available. It is this mode of star formation which is responsible for the intense starbursts observed in the early Universe. In order to achieve this understanding, we need to measure how the efficiency with which stars are formed from Galactic molecular gas clouds, and the distribution of the masses of the new stars that form, change with the strength of the physical forces which impact on the clouds, such as the winds and expanding ionised regions associated with hot stars, and supernova explosions. We also need to understand the initial conditions of star formation: the origin of the clouds themselves, their characteristic turbulence and how spontaneous star formation is affected by differences in these conditions. We have made significant progress in this direction with comprehensive observational studies of the star-formation content of single Galactic, star-forming, giant molecular clouds. Progress now requires large samples of similar regions with different initial and environmental conditions. The applicant is leading an international project to survey the Plane of the Galaxy using new, STFC-funded, state-of-the art instrumentation at the James Clerk Maxwell Telescope in Hawaii. This survey will produce a census of all high-mass star formation in a large fraction of the Galaxy which will lead to significant advances in the field. It will allow, for the first time, the study of representative samples of star-forming regions with a variety of internal and external physical environments. The applicant is also a key active member of an international consortium that has secured 300+ hours of observing time on the Herschel far-infrared space observatory, in order to survey the inner Galactic Plane. This project will provide important data on luminosities and temperatures (hence evolutionary status) for all but the coldest sources detected with SCUBA-2 in the inner Galaxy region. The proposed research will reveal the quantitative effect of initial conditions, external environment, and feedback on the star-formation efficiency and structure mass function. The results will create advances in our understanding of star formation and provide valuable input into other fields, such as the study of formation and evolution of galaxies.