Integrating precision observations and simulations of the Intergalactic Medium

University Of California-San Diego, La Jolla CA

Investigators

Abstract

AST-0808168 Tytler The intergalactic medium is most of the volume of the Universe and until recently it contained most of the dark matter and gas. This project is a tight combination of precision measurements of the intergalactic medium through absorption in quasar spectra with a suite of simulations designed to extract the physical parameters from those measurements. It will provide new estimates of cosmologically interesting parameters, including the baryonic, dark matter and dark energy contents, and the amount of clustering of matter on small scales, which are more accurate than those obtained before from the intergalactic gas, and completely independent of those from supernovae, galaxies and the cosmic microwave background. For all parameters the errors will be comparable to the best of any method. The work will also give much more accurate measurements of the temperature of the intergalactic gas, and the intensity of the ultraviolet background radiation. Sophisticated calibrations of spectra will make them suitable for determining which set of parameters makes the simulated spectra most like the real spectra. Some simulations will include radiative transfer so as to interpret absorption near to individual quasars. This team has a long record of integrating education and diversity with their research. Students receive intensive instruction in astrophysics, cosmology and the methods of precision measurement, observing with the Keck and Lick telescopes, and learn to run a large code on state-of-the-art supercomputers. Most undergraduates will also become co-authors on one or two papers.