Deep Field

Tiny Old Galaxies Lab

Near Field Cosmology,
Local Group Galaxy Evolution.

TOGL studies near–field cosmology and galaxy evolution using both optical telescopes and cosmological simulations. In particular, my work focuses on ultra–faint dwarf galaxies — researching these possible relics of the first galaxies ever formed to learn more about the early universe, how the earliest galaxies evolve, and how they can be used as a tool to learn more about our own galaxy, the Milky Way. My students also study variable stars living in the Milky Way to learn about our own galaxy from within.

Tiny Old Galaxies Lab

TOGL's Work Online

Links to academic work and professional presence.

Ultra Faint Dwarf Galaxy

Ultra Faint Dwarf Galaxies

Within TOGL, we explore the chemical evolution and formation histories of ultra-faint dwarf galaxies (UFDs), relic systems believed to be the first galaxies to form in the Universe. Through detailed spectroscopic analyses of stars in systems like Hydrus I and Willman 1, we measure metallicities and elemental abundances to investigate the low-mass end of the stellar mass–metallicity relation and constrain UFD origins. Looking forward, I aim to integrate these empirical results with cosmological simulations and semi-analytic models, to illuminate UFD evolutionary pathways and guide interpretation of LSST-scale surveys in Near-Field Cosmology.

Milky Way

The Local Group

Another topic of research within TOGL uses the kinematics of Milky Way stars and satellites to probe the structure and evolution of our galaxy and its place in the Local Group. Our work combines large datasets from RR Lyrae stars—including a forthcoming 6D phase-space catalog calibrated with spectroscopic radial velocities—to refine measurements of the Milky Way’s dark matter halo mass. Building on this, we compare satellite galaxy dynamics to subhalo populations in simulations (e.g., Phat ELVIS) to constrain host halo properties, and explore the transition from isolated to environmentally quenched systems. Future work will extend these efforts with cosmological models and deep spectroscopic studies to reveal how satellite accretion histories, reionization, and galaxy–halo co-evolution shaped the present-day Local Group.