Sam Cutler (Tufts University)

Title: The Structure and Formation Histories of Low-Mass Quiescent Galaxies in Overdense Environments
Abstract: Low-mass quiescent galaxies are thought to predominantly reside in overdense regions, as environmental effects are often invoked to explain their shutdown of star formation. These longer-timescale quenching mechanisms leave imprints on galaxy morphologies, emphasizing the importance of quantifying the structures of low-mass quiescent galaxies in overdensities. In this talk, I present the first measurement of the quiescent size-mass relation between 7<logM<10 in the z=0.308 Abell 2744 galaxy cluster, utilizing James Webb Space Telescope imaging from the UNCOVER and MegaScience programs. The resulting size-mass relation has a significantly higher scatter than similar-redshift field samples, despite comparable best-fit relations in both the dwarf and intermediate-mass regimes, suggesting a general expansion of galaxy structure from dynamical interactions could be at play. The SFHs derived for our cluster sample imply their formation and quenching occurs relatively late, at z<1.5, which disfavors an onset of quenching due to the environment in cosmic noon populations. Using high-quality medium-band photometry from the MINERVA program, I present future avenues that leverage improved photometric redshifts to study low-mass quenching in overdensities across redshifts 1-2.

Biography: Sam is an Astronomy Postdoctoral Researcher at Tufts University with the JWST Cycle 4 MINERVA team. He obtained his Ph.D. in Astronomy at the University of Massachusetts, Amherst in September 2025 advised by Kate Whitaker. In present research, Sam focuses on the formation and evolution of galaxies via large photometric and spectroscopic surveys and galaxy morphology. (Adapted from https://samecutler.github.io)

Eliot Vrijmoet (Smith College)

Title: What's the Big Picture? Capturing All the Companions to the Lowest-Mass Stars
Abstract: The M dwarfs are frequently orbited by other low-mass stars and terrestrial planets, yet rarely by other substellar objects between those mass regimes --- i.e., rarely by brown dwarfs and Jovian planets. The collective orbital architectures of those unusual substellar companions thus present a valuable opportunity to learn about those objects' formation, dynamical evolution, and original circumstellar environments. Accessing those parameter spaces, however, requires complementary observing techniques to truly map the orbits and thoroughly assess the masses and mass ratios that occur. Here we present the our pilot study of several M dwarfs with strong evidence of potentially substellar companions, combining 20+ years of astrometric monitoring from RECONS with high-precision radial velocity snapshots from Maroon-X on Gemini-N. Together, these powerful data sets will let us detect and characterize substellar orbits beyond the typical limits of each technique alone. We will present preliminary results from this study as well as our plan for the "dream survey" --- to detect all substellar companions in the local neighborhood orbiting on periods spanning days to decades.