Feeding and Feedback: Understanding the Assembly of Galactic Disks

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

The growth of galaxies occurs as the galaxies gather gas from their surroundings to produce stars. The stars will then produce a 'wind' that is driven by starlight and energetic particles along with supernovae from the explosion of more massive stars. This wind serves to drive gas away from the galaxies which slows down the star formation rate. This project will study the flow of gas in and out of star forming galaxies by looking at how the light from distant quasars is absorbed as it passes through the gas surrounding the more nearby star forming galaxies. The project will also compare their results with cosmological simulations to better understand both the simulations and the status of the galaxies. The project will also enhance the educational opportunities for underrepresented minorities from elementary school to the graduate level. As galaxies grow, they accrete gas from their surroundings to feed their star formation. As they form stars, they produce a galactic wind that drives gas away. This project will study the flow of gas in and out of star forming galaxies. The flow of the gas will be measured by observing absorption lines from circum-galactic gas lying along the line-of-sight to distant quasars. This will give us a better understanding of how gas flows in and out of galaxies as they grow. The project will analyze 50 new sightlines, sampling the circum-galactic medium (CGM) around several typical star forming galaxies. The project will then compare these results with cosmological simulations of galaxy formation, using the EAGLE simulations. The project will also perform a ?Look Back Study? by comparing galaxies at redshifts of ~0.2 with their lower mass progenitors a redshifts of 2. In this part, the project will look at clumpy distant galaxies and statistically determine if the clumpiness can be related to different outflows of gas. The project will also enhance the educational opportunities for underrepresented minorities from elementary school to the graduate level. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.