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Imaging Supermassive Black Holes: From Still Images to Video

Lecture of Sheperd Doeleman, Harvard University

Time: Thu 2023-10-12 15.00 - 16.00


Language: English


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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: through observations of the supermassive black hole at the center of galaxy M87, we have seen the predicted strong gravitational lensing that matches the theory of General Relativity (GR). In 2022, observations of SgrA*, the black hole at the center of our Milky Way galaxy, revealed a similar ring with dimensions predicted by GR. These results have now opened the door to precision measurement of black holes on horizon scales, and next-generation enhancements to the array allow us to anticipate black hole movies by the end of this decade.

This talk will cover how this was accomplished, the impact, and what the future holds for the study of black holes.

Supported by the Swedish Royal Academy of Sciences through its Nobel Institute for Physics.
Part of the Manne Siegbahn Memorial Lecture Series