Title: "Imaging Magnetic Fields at the Event Horizon of a Black Hole" (Video)
Abstract: Magnetic fields play a central role in the accretion, emission, and outflow near black holes but have never been directly observed in this region. Yet, because linear polarization of the bright synchrotron emission from galactic cores traces these magnetic fields, polarimetric interferometry with the Event Horizon Telescope (EHT) is capable of imaging these near-horizon fields. I will present EHT observations of the Galactic Center supermassive black hole, Sgr A*. These observations, the first to resolve the polarized emission from Sgr A* at any wavelength, revealed ordered magnetic fields with vigorous activity near the event horizon. I will also discuss the emerging capabilities of the EHT to study turbulence driven by the magnetorotational instability, the role of magnetic fields in jet launching, and signatures of magnetically-dominant regions near supermassive black holes.