Studying the Threshold of Galaxy Formation with Ultra-Faint Galaxies

The Milky Way is surrounded by dozens of “ultra-faint” satellite galaxies. Observations of these galaxies inform our understanding of how galaxies form and evolve. However, ultra-faint galaxies are difficult to detect and challenging to study. The investigators will use astronomical imaging data to perform a census of ultra-faint satellite galaxies in the local Universe. These observations will be compared to predictions to provide new insights into the formation of galaxies and the nature of the dark matter halos that they inhabit. This project will enhance public access to state-of-the art astronomical data. Furthermore, the investigators will engage the public through citizen science projects and train the next generation of scientists. The investigators will use multi-band imaging data from the DECam Local Volume Exploration (DELVE) survey to perform a statistically rigorous census of ultra-faint galaxies around the Milky Way, the Magellanic Clouds, and Magellanic-analog galaxies in the Local Volume. By combining observed satellite populations, observational selection functions, and cosmological simulations in a unified framework, it will be possible to measure the relationship between dark matter halos and galaxies at the smallest accessible scales. These observations will provide a powerful test of the standard model of cosmology and galaxy formation in a previously inaccessible regime. The tools and expertise that are developed as part of this project will enhance early science with the NSF’s Vera C. Rubin Observatory. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.