University of Arizona
Christopher Impey is an astronomy researcher and educator focused on studying distant galaxies and black holes from his vantage point on Earth. He has designed projects that use radio and X-ray wavelengths to characterize the nuclei of galaxies and has worked intimately with astronomy’s premier facility—the Hubble Space Telescope—to probe quasars, the brightest sources of light in the universe. He has made substantial contributions to a number of areas of extragalactic astronomy and cosmology.
Many galaxies throughout the universe are classified as active galaxies—at their centers, or nuclei, are supermassive black holes emitting electromagnetic radiation. Impey’s research career began with explorations of blazars, one type of active galactic nucleus. He showed that the properties of a blazar were consistent with emissions near a supermassive black hole, setting the stage for scientists’ current understanding of active galaxies. The work extended into characterizing the global energetics of active galaxies using observations ranging from radio to X-ray wavelengths.
In the late 1980s, Impey began large surveys of low surface brightness galaxies throughout the nearby universe and co-discovered the largest known spiral galaxy, named Malin 1 after his collaborator. More recently, Impey has turned his attention to quasars—a highly luminous type of active galactic nucleus. He has used quasars as probes to study intergalactic medium—the void in space between galaxies—and launched a project to characterize quasars in the Cosmic Evolution Survey, a Hubble Space Telescope Legacy project. This led to the discovery of intermediate mass black holes at high redshift and a determination of the range of quasar accretion efficiency.
Over 28 years as a professor, Impey has taught at all levels, but has specialized in the teaching of general astronomy courses to non-science majors. In the classroom, he has pioneered a range of interactive, learner-centered methods for education: labs, data-rich activities, Socratic dialogs, writing portfolios, debates, creative projects, social media, audience response devices, the use of undergraduate learning assistants, and the use of virtual worlds such as Second Life. To encourage science literacy—among both his students and the broader public—he created the teaching website for the University of Arizona’s Department of Astronomy. In the past two years, the site has had over 55,000 unique visitors. In recognition of his teaching, Impey has been named an National Science Foundation Distinguished Teaching Scholar, a Phi Beta Kappa Visiting Scholar, and the 2002 Arizona Professor of the Year.
In addition to leading the nation’s largest undergraduate majors program in astronomy and second largest astronomy PhD program in the country, Impey engages with the public and with students at other institutions through online courses and writing. He is currently teaching an online class with an enrollment of more than 14,000 students and he has authored more than 40 popular articles on cosmology and astrobiology, two introductory textbooks, a novel, and six popular science books.