The extragalactic group's current members employ a wide range of observational and theoretical tools (with an emphasis on optical, radio and X-ray astronomy and computational astrophysics) in an attempt to understand the origin, dynamics, and evolution of both active and normal galaxies.
- Alberto Bolatto uses ground and space facilities to study the effects of heavy element abundance on the physics of the interstellar medium, the relationship between gas, dust, and star formation in galaxies, and the properties of dark matter galaxy halos in nearby galaxies.
- Suvi Gezari is an observational astronomer who studies supermassive black holes and core-collapse supernovae using time domain surveys and multiwavelength follow-up observations.
- Andrew Harris studies the energetics and physical conditions within galaxies and their nuclei, including our Galactic center, and he develops instrumentation for radio observations over wide bandwidths and wide fields of view.
- Richard Mushotzky is a renowned expert in high-energy studies of clusters of galaxies and active galactic nuclei.
- Massimo Ricotti is a theoretical cosmologist interested in high redshift galaxy formation, nearby dwarf galaxies, and the physics of the intergalactic and interstellar medium.
- Sylvain Veilleux is an observer whose work centers on understanding the nature of starburst and black-hole driven activity in galaxies.
- Stuart Vogel studies the dynamics and evolution of galaxies with CO observations with the CARMA array of telescopes.