Early Galaxy and Quasar Science from Millions of DESI Spectra

The Dark Energy Spectroscopic Instrument (DESI) survey has obtained observed-frame optical spectrophotometry for millions of galaxies and quasars at 0<z<4, making it among the largest datasets of extragalactic sources ever assembled. The sheer size and quality of the DESI survey data will yield transformative insights into the formation and evolution of galaxies and quasars, as well as on the physics of the baryon cycle over eighty percent of cosmic time. In this contribution, we highlight some of the initial science results from the first year of DESI observations, including work on the star formation and nuclear activity in low-mass galaxies; the stellar mass-metallicity relation; post-starburst galaxies; the content and velocity structure of the circumgalactic medium; and more.