Type: Talk
Session: Stellar Science and Crowded Fields
Author: Aaron Meisner

Abstract: Modern optical surveys have enabled tomography of the Milky Way using populations such as main sequence turnoff stars. The Milky Way's cold, substellar population also carries a wealth of information about our Galaxy's structure and the star formation process at low masses, but thus far studies of these coolest objects have been limited to the Sun's very local neighborhood. The combination of deep near-infrared and red-optical survey data from Roman and Rubin/LSST will vastly expand the volume covered by samples of cold (sub)stellar objects, allowing us to: map the Galaxy's scale height into the L and T spectral classes, understand any metallicity dependence toward the bottom of the substellar mass function, characterize the stellar/substellar boundary's evolution with metallicity, trace low-mass star formation over cosmic time, and probe the age versus temperature relation of brown dwarf cooling.