Colloquium Schedule

Spring 2024

Astronomy Re-envisioned: Investigating the Physics of Galaxy Evolution with Machine Learning

John Wu, Space Telescope Science Institute
Friday, March 1 at 12:45

Astronomical imaging of galaxies reveals how they formed and evolved. While spectroscopy is necessary for measuring galaxies' physical properties, such as their cold gas content or metallicity, it is now possible to reliably predict these properties direct from three-color optical image cutouts by using convolutional neural networks (CNNs). Even the entire optical spectrum can be determined purely from galaxy images. We have also found that highly optimized CNNs can robustly identify nearby dwarf galaxies from large-area imaging surveys, resulting in a dramatic increase in the total number of satellite galaxy systems we can study at low redshifts. Finally, we present a novel theoretical approach for modeling galaxies, dark matter halos, and their cosmic surroundings using graph neural networks. These applications are prime examples of how deep learning can facilitate new discoveries in galaxy evolution and near-field cosmology. 

Seeing Is Believing – How X-ray Probes Can Help Us Understand Solid State Batteries

Kelsey Hatzell, Princeton University
Friday, March 29 at 12:45

New and re-imagined energy materials play a critical role in decarbonizing a range of industries related to transportation, chemical fuels, separations, power production and beyond. Transportation accounts for approximately 23% of energy related carbon dioxide emissions and electrification approaches are widespread for personal vehicles. Batteries currently play an outstanding role in a range of applications including electric vehicles and portable electronic applications and there is a growing interests in expanding the frontier for batteries. Applications such as electric aviation, batteries in space applications, and undersea propulsion all present unique engineering and scientific challenges for electrochemical energy storage systems. In this talk I will discuss emerging battery systems which move ions (e.g. charge carrier) in a solid rather than a liquid. I will also discuss the materials and chemo-mechanical principles which impact ion transport and electron transfer reactions in this class of material systems. Understanding how to engineer materials for coordinated and/or concerted transport is critical achieving reversible operation of these materials and devices. Using real- and reciprocal- space techniques I will show how we can measure and visualize material utilization and reaction heterogeneity in solid state batteries in space and time. The talk will conclude by exploring emerging applications for energy and climate materials through highlighting some of our team’s emerging directions that focus on batteries for space applications and novel moisture-swing direct air capture processes.