School of Physics Spring Colloquium Series-Dr. Lia Medeiros

Speaker: Dr. Lia Medeiros

Host: Matthew Liska

Title:  EHT images of black holes: what we've learned from them and how we can improve them

Abstract: Horizon-scale images of the Galactic Center black hole Sagittarius A* (Sgr A*) published by the Event Horizon Telescope (EHT) in 2022 allow for strong-field tests of the Kerr metric in a previously unexplored regime. I will discuss the EHT observations of Sgr A* with a particular focus on how these results can be used to test fundamental physics. I will briefly touch upon the earlier M87 results as well. In the second half of my talk I will discuss how we can improve upon these results. I will introduce PRIMO, a new machine-learning algorithm for EHT data analysis, which uses a large library of high-fidelity simulations as a training set. Finally, I will show a new higher-resolution image of the black hole in M87 reconstructed with PRIMO.

Bio: Dr. Medeiros is an Assistant Professor at the University of Wisconsin, Milwaukee (UWM). Before arriving at UWM she was a NASA Hubble Fellowship Program, Einstein Fellow at Princeton University, was a member of the Institute for Advanced Study (IAS) from 2019 to 2023 and was a National Science Foundation (NSF) Astronomy and Astrophysics Postdoctoral Fellow from 2019 to 2022. She completed her undergraduate education at the University of California-Berkeley in Physics and Astrophysics and received her Masters and PhD (2019) in Physics from the University of California-Santa Barbara. After completing her classes in Santa Barbara, she took advantage of the flexibility allowed by an NSF Graduate Research Fellowship and spent three years at the Steward Observatory at The University of Arizona and one year at the Black Hole Initiative at Harvard.