Together with Jim Schombert and Federico Lelli, McGaugh has assembled the SPARC database of galaxies with rotation curves and Spitzer surface photometry. Together, these provide accurate mass models for nearly 200 rotationally supported disk galaxies, mapping the distribution of their mass components in detail, and providing the most accurate assessment of the stellar mass of galaxies currently available. The SPARC database has been widely used by other, and has become a touchstone for many theoretical as well as observational investigations.
In addition to his observational work, he has also played theorist on occasion, successfully predicting the velocity dispersions of dwarf galaxies like Crater 2 and Andromeda 28 (and many other Local Group dwarfs), the declining slope of the rotation curve of the Milky Way, the stability properties of low surface brightness disks, the early reionization of the universe and the strong absorption signal observed in the EDGES experiment, and the first-to-second peak amplitude ratio of the acoustic power spectrum of the cosmic microwave background.
McGaugh studied at MIT, Princeton, and the University of Michigan. He is a distinguished alumnus of both Flint (MI) Norhern High School and the Astronomy department of the University of Michigan. McGaugh was a research fellow at the Institute of Astronomy at the University of Cambridge, the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, and Rutgers before joining the faculty of the University of Maryland in 1998. In 2012, he moved to Case Western Reserve University where he served as the Chair of the Department of Astronomy and Director of the Warner and Swasey Observatory from 2015 to 2022.