Sean Johnson

Sean Johnson is an Assistant Professor of Astronomy, LSA Collegiate Fellow, and Rackham Faculty Ally in the Department of Astronomy at the University of Michigan. He earned his PhD in Astronomy and Astrophysics from the University of Chicago in 2016. Before joining the University of Michigan, Johnson was a Hubble and Carnegie-Princeton Postdoctoral Fellow at Princeton University, where he volunteered regularly with the Prison Teaching Initiative.

Sean Johnson is an observational astronomer who studies galaxies, supermassive black holes, and the surrounding gas supplies that fuel their growth. He combines datasets from space-based and large ground-based telescopes to examine the physical conditions of gas supplies that enable galaxies to form stars and to identify chemical signatures of heavy elements produced in supernova explosions and deposited into intergalactic space by galactic-scale winds and galaxy interactions. He is co-PI of the Cosmic Ultraviolet Baryon Survey (CUBS) and leads wide-field ground-based follow-up for the MUSE Quasar Blind Emitter Survey (MUSEQuBES), increasing samples for circumgalactic medium studies at z<1 by more than an order of magnitude using HST UV spectra, MUSE integral field observations, and Magellan galaxy surveys. Key publications include "Directly tracing cool filamentary accretion over >100 kpc into the interstellar medium of a quasar host at z=1" (ApJ Letters, in review); "Improving blazar redshift constraints with the edge of the Ly α forest: 1ES 1553+113 and implications for observations of the WHIM" (MNRAS, 2022); "Discovery and origins of giant optical nebulae surrounding quasar PKS 0454-22" (MNRAS, 2021); "Spatially Resolved UV Diagnostics of AGN Feedback: Radiation Pressure Dominates in a Prototypical Quasar-driven Superwind" (ApJ Letters, 2020); "Galaxy and Quasar Fueling Caught in the Act from the Intragroup to the Interstellar Medium" (ApJ Letters, 2018); and "The Extent of Chemically Enriched Gas around Star-forming Dwarf Galaxies" (ApJ Letters, 2017).

Professional Email: seanjoh@umich.edu