Caltech/IPAC Lunch Seminar

Low-mass galaxies provide a sensitive probe of the physical processes that regulate galaxy growth, including star formation, dust attenuation, feedback, and gas cycling. Because of their shallow potential wells and relatively low dust content, these systems are expected to respond strongly to both internal feedback and external environmental effects. I will present a spectroscopic study of low-mass galaxies in the COSMOS field, focusing on their star formation rates, dust attenuation properties, and the connection between nebular and stellar reddening. Using optical spectroscopy, we find that low-mass galaxies follow a nearly scale-free SFR–stellar mass relation. At the same time, their dust attenuation behavior differs from that of more massive galaxies, with lower and less mass-dependent nebular attenuation, suggesting that feedback and efficient dispersal of birth clouds play an important role in shaping their interstellar medium. I will also discuss how this work connects to ongoing JWST/PASSAGE studies of low-mass galaxies in and around a protocluster at cosmic noon. By extending measurements of the SFR–mass relation and gas-phase metallicity to lower stellar masses in both field and overdense environments, these observations provide a path toward testing whether environment affects the baryon cycle during the epoch of peak galaxy assembly. Together, these studies use low-mass galaxies as laboratories for understanding how star formation, feedback, dust, and environment jointly shape galaxy evolution across cosmic time.