Steward Observatory/NSF’s NOIRLab Joint Colloquium Series: Resolving the Galactic Center Black Hole with the Event Horizon Telescope

Abstract: In 2017, the Event Horizon Telescope (EHT) observed the Galactic Center supermassive black hole Sagittarius A* (Sgr A*) using a global interferometric array of 8 telescopes. The resulting horizon scale images provide a unique opportunity to constraint the astrophysics of black hole accretion and to test Einstein's general theory of relativity in the strong field regime. In this talk, we will introduce the EHT project and go over its data pathway and imaging methods. We will acknowledgement the many researchers at the Univeristy of Arizona who make these images possible. By comparing EHT's Sgr A* images with a large simulation library, we constraint the property of the accretion flows around the Galactic Center black hole. By comparing the geometric shadow boundary and the observed size of the ring-like images, we show that EHT's observations are consistent with the predictions of general relativity.

• Graduate students will meet with the colloquium speaker for lunch on Sept. 1st at 12:00 PM (AZ) in the Steward Observatory tea area.