On the Formation and Destruction of Giant Molecular Clouds in Galaxies

如果我们要了解太阳和地球是如何形成的，我们必须首先了解银河系本身是如何形成的，以及它是如何随时间变化的。天文学家知道银河系包含巨大的气体云和尘埃云。所有的恒星都是从这些“巨分子云”中诞生的。这个项目的目标是了解这些巨大的云是如何形成的，以及它们在数百万年里是如何变化的。利用多年来开发的计算机模型，获奖者将研究超大恒星的爆炸如何影响云。这些模型包含了许多已知会影响银河系气体的因素：气体的温度和密度、银河系的自转、星系中数十亿颗恒星发出的光，甚至是云中原子和分子的化学成分。大部分工作将由博士后研究员完成，由首席研究员（PI）指导，他是银河系天文学和恒星诞生方面的世界知名专家。研究生和本科生也将参与这项研究，女高中生将被邀请到PI的研究所跟随毕业生和早期职业科学家。通过这种方式，PI希望激励新一代年轻的女性研究人员。该项目旨在继续在非常大的空间尺度（gmc及以上）上对恒星形成进行数值模拟。新的模型将包括电离和非电离紫外线辐射、超新星反馈、湍流、磁场、化学和星系剪切。这些影响中的许多都被排除在过去的模型之外，或者单独使用而不是组合使用。该项目将采用先进的计算方法模拟GMC的形成和破坏，提供第一个高分辨率、物理和化学综合处理的完全自一致磁流体动力学（MHD）和辐射MHD模型。这样的模型不仅在银河系的恒星形成和GMC演化中有用，而且可以用来解释ALMA对其他附近星系的新观测。

If we are to understand how the Sun and Earth formed, we must first understand how the Galaxy itself was formed and how it changes over time. Astronomers know that the Milky Way Galaxy contains huge clouds of gas and dust. It is from these "Giant Molecular Clouds" (GMCs) that all stars are born. The goal of this project is to understand how these giant clouds are formed and how they change over millions of years. Using computer models developed over a number of years, the awardee will investigate how the explosions of very large stars affect the clouds. The models include many of the things known to affect the gas in the Milky Way: the temperature and density of the gas, the rotation of the Milky Way, the light from the billions of stars in the galaxy, and even the chemistry of the atoms and molecules in the clouds. Much of the work will be done by a postdoctoral researcher, guided by the Principal Investigator (PI) who is a world-renown expert in Milky Way astronomy and the birth of stars. Graduate and undergraduate students will also be involved in the research, and female high-school students will be invited to the PI's institute to shadow graduates and early-career scientists. In this way the PI hopes to inspire a new generation of young, female researchers.The project seeks to continue numerical modeling of star formation on very large spatial scales (GMCs and above). The new models will include ionizing and non-ionizing UV radiation, supernova feedback, turbulence, magnetic fields, chemistry, and galactic shear. Many of these effects have been excluded from past models or used individually rather than in combination. This project will use advanced computational methods to simulate GMC formation and destruction, providing the first fully self-consistent magnetohydrodynamic (MHD) and radiation MHD models at high resolution and with comprehensive treatment of physics and chemistry. Such modeling is useful not only in synthesizing star formation and GMC evolution in the Milky Way Galaxy but may also be used to interpret new ALMA observations of other, nearby galaxies.