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Thursday, 12 Oct. 2023 |
Video-Recording for any system with MP4-support - Video.mp4 (ca. 442 Mb) |
15:15 – 16:23 |
Manne Siegbahn
Memorial Lecture 2023:
“Imaging Supermassive
Black Holes: From Still Images to Video”
Prof.
Sheperd Doeleman
(Center for Astrophysics, Harvard & Smithsonian and
Founding Director
of the Event Horizon Telescope (EHT))
Abstract:
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.
About the speaker:
Sheperd
S. Doeleman is an Astrophysicist at the Center for
Astrophysics,
Harvard & Smithsonian and Founding
Director of the Event Horizon Telescope
(EHT), a synchronized global array of
radio observatories designed to
examine
the nature of black holes. He is also a Harvard Senior Research
Fellow and a Project Co-Leader of
Harvard’s recently established Black
Hole Initiative. Doeleman now leads the next-generation Event Horizon
Telescope project.