Jose Benavides & Bobby Pascua

Talk 1: Jose Benavides, 3:00pm -  3:30pm
Morphological transition in simulated low-mass galaxies in FIREbox
Disk formation in galaxies is a central topic in understanding galactic evolution and the small-scale structure of the Universe. Low-mass galaxies (M* < 10^10 Msun) exhibit significant morphological diversity, with many showing dynamics dominated by velocity dispersions rather than rotational support. In this work, we investigate the physical factors that influence disk formation in these galaxies, focusing on the interaction between stellar feedback and internal gas dynamics, using data from the FIREbox and FIRE zoom-ins cosmological simulations. We demonstrate how disk formation in low-mass galaxies is possible under certain conditions, such as high dark matter halo spin, the presence of cold gas with high angular momentum capable of forming young stars with rotational support, and even interactions with satellites that induce a disk structure. Additionally, we report a morphological transition from spheroidal to disky galaxies in the range of M* ~ 10^9 Msun. These findings provide detailed insights into the mechanisms governing the formation of galactic structures in low-mass regimes, with important implications for models of galaxy formation and the evolution of galaxies across the Universe.

Talk 2: Bobby Pascua, 3:30pm - 4:00pm
Constraining reionization with HERA
The Hydrogen Epoch of Reionization Array (HERA) is an SKA-precursor instrument designed to detect fluctuations in the highly redshifted 21-cm signal from neutral hydrogen throughout Cosmic Dawn and the Epoch of Reionization. In 2023, HERA published the most stringent limits to-date on the 21-cm power spectrum using data from the "Phase I" design of the instrument. Analysis is currently underway to produce more sensitive limits using data taken with the "Phase II" design of the HERA instrument, which features a new signal chain and new widefield feed with increased bandwidth. New electronics and increased sensitivity require developing a new understanding of systematics in the data as well as new techniques for mitigating those systematics. In this talk, I will present HERA's latest results and discuss their astrophysical implications. I will describe recent advances in modeling and mitigating mutual coupling, a pressing systematic that may preclude detection of the 21-cm signal if not appropriately mitigated. I will conclude with an outlook for the future based on lessons learned from HERA.