Absorption-line Gas: Combining Models and Observations

University Of California-Irvine, Irvine CA

Investigators

Abstract

The PI and co-PI of this project will combine observational and theoretical efforts to understand how ordinary (baryonic) matter flows into and out of galaxies in different environments. The observational side of the project will focus on galaxies identified in the Sloan Digital Sky Survey (SDSS) with known star-forming properties that have quasars behind them. By obtaining spectra of the quasars and analyzing absorption lines due to once-ionized magnesium (Mg II) and neutral sodium (Na I) in the galaxies, they will determine the spatial extent of inflow or outflow signatures and whether they are correlated with star formation rate or environment. They will also analyze the Na I D line in lower luminosity galaxies, using spectra from the SDSS and DEEP2 surveys. The theoretical side of the project will use cosmological hydrodynamic simulations to calculate model profiles of the Mg and Na lines, in order to interpret the observations and identify signatures of "cold flow" accretion. The results from this study will inform the science justifications for, and implicitly the design of, next-generation ground-based telescopes. Also, the PI and co-PI, as instructors in the California State Summer School for Mathematics and Science, will develop a laboratory project using elements of their research for high-school students.