This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Dr Steidel will make a detailed study of the galaxies and gas within a few million light years of bright quasars that we observe as they were 10 billion years ago. Using the Keck telescopes, he will take high-resolution optical and near-infrared spectra to measure the absorption lines of gas lying between us and the quasar. These spectra will target lines of highly ionized oxygen to trace warm and hot gas, Lyman-beta to measure neutral hydrogen, and additional lines that probe the chemical abundance and physical conditions in the gas. These observations will be compared with theoretical models for the effect that active galactic nuclei such as quasars should have on their surroundings. Deep optical and near-infrared images will be taken to pick out galaxies likely to lie close to the quasar. Optical and infrared spectra of these objects should yield accurate redshifts (and hence distances), dynamical masses and chemical abundances for about 150 galaxies around each quasar. The infrared spectroscopy should be particularly effective when the galaxies are partially obscured by dust.
Two or three graduate students will be trained as they participate in the research. Both the published results and primary data will be made available as soon as possible to the astronomical community. Dr Steidel is Project Scientist for the MOSFIRE imaging spectrograph (Multi-Object Spectrometer for InfraRed Exploration); this new instrument will serve the Keck Observatory's large user community.
