Vadim Semenov (Center for Astrophysics, Harvard & Smithsonian) - Bridging Scales and Cosmic Epochs of Turbulent Galaxy Formation

Our paradigm of galaxy formation has been transformed by observations from new instruments such as JWST, ALMA, and Gaia, which now allow us to probe the structure of the Milky Way and nearby galaxies in exquisite detail while simultaneously revealing the first galaxies emerging at cosmic dawn. This unprecedented dual perspective has uncovered significant tensions with existing theoretical models, such as the surprisingly rapid maturation of galaxies, the large abundance of bright systems at early times, and the early emergence of galactic disks, including that of our own Milky Way. Large-scale cosmological simulations provide a unique theoretical laboratory for testing and falsifying models of galaxy formation, and will remain indispensable for transforming the next generation of observations into physical understanding. However, to bridge the scales and cosmic epochs uncovered by new observations, such simulations must be placed on a firm physical footing, enabling prediction -- rather than extrapolation -- of key physical processes operating in unexplored, extreme environments, such as those of the early Universe. In this talk, I will outline ongoing efforts to develop predictive, physically grounded models and frameworks that connect the physics of individual star-forming regions to the turbulent formation and growth of galaxies in a cosmological context, which sheds fresh light on these observational discoveries.

Astronomy Colloquium covers a wide range of topics and should be accessible to advanced Astronomy Majors. Refreshments will be served from 3:45 pm with the presentation beginning at 4:00pm.