On the Formation and Destruction of Giant Molecular Clouds in Galaxies

Princeton University, Princeton NJ

Investigators

Abstract

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.