Ångström Lecture 2021: Imaging a black hole with the Event Horizon Telescope
- Date: –16:15
- Location: Lecture via zoom
- Lecturer: Sheperd S. Doeleman, Smithsonian Astrophysicist and Harvard Senior Research Fellow
- Organiser: Ångström Lecture Committee with support från the Royal Swedish Academy of Sciences
- Contact person: Joseph Nordgren
- Phone: 018-471 3554
Black holes are cosmic objects so compact that not even light can escape their gravity. Until recently, no one had ever seen what a black hole really looked like. Using a network of radio telescopes, a research team has imaged a black hole. The Ångström lecture will describe how this was achieved and tell about plans that enable real-time films of black holes.
Black holes are cosmic objects so small and dense, that nothing, not even light can escape their gravitational pull. Until recently, no one had ever seen what a black hole actually looked like. Einstein's theories predict that a distant observer should see a ring of light encircling the black hole, which forms when radiation emitted by infalling hot gas is lensed by the extreme gravity near the event horizon.
The Event Horizon Telescope (EHT) is a global array of radio dishes, linked together by a network of atomic clocks to form an Earth-sized virtual telescope that can resolve the nearest supermassive black holes where this ring feature may be measured.
On April 10th, 2019, the EHT project reported success: we have imaged a black hole, seen the predicted strong gravitational lensing that confirms the theory of General Relativity at the boundary of a black hole; and most recently mapped magnetic fields near the horizon. This talk will cover how this was accomplished, details of the first results, as well as future directions that will enable real-time black hole movies.