B.S. New Mexico Institute of Mining and Technology (1983)
Ph.D. Montana State University (1991)
I am an observational multiwavelength astronomer who studies quasar astrophysics. Over the span of my career, I have investigated central engine properties using X-ray spectral and variability information from EXOSAT, Ginga, ROSAT, ASCA, BeppoSax, RXTE, Chandra, XMMNewton, and Swift satellites. I have studied the astrophysics of the broad line region using ground-based optical and infrared observations, and UV observations from HST. Currently I am interested in quasar outflows revealed by the broad absorption lines that are observed in the rest-frame optical, UV, and infrared bands of about 20% of quasars. Open questions include the location of the outflow in the quasar and host galaxy, the acceleration mechanisms of the outflow, and the relationship between outflow properties and the accretion properties of the quasar central engine. Our spectra come from the Sloan Digital Sky Survey and ground-based observatories including APO, Gemini, and LBT. I am the PI of the SimBAL project (simbal.ouml.org), a novel spectral synthesis method for analyzing broad absorption line quasar spectra. I am a collaborator on the 4MOST Purely Astrometric Quasar Survey (PAQS), a project that will yield a sample of quasars with straightforward and easily correctable selection effects. 4MOST observations will begin in 2024.