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| An artist's impression of a black hole warping space-time around it. Astronomers used this phenomenon, called gravitational lensing, to detect one of the largest black holes ever found in the universe. (Image credit: ESA/Hubble, Digitized Sky Survey, Nick Risinger (skysurvey.org), N. Bartmann) |
Astronomers have discovered one of the largest black holes ever found — an
ultramassive monster roughly 30 billion times the mass of the sun — using a
space-time trick predicted by Albert Einstein.
A team of astronomers has discovered one of the biggest black holes ever
found, taking advantage of a phenomenon called gravitational lensing.
The team, led by Durham University, UK, used gravitational lensing—where a
foreground galaxy bends the light from a more distant object and magnifies
it—and supercomputer simulations on the DiRAC HPC facility, which enabled
the team to closely examine how light is bent by a black hole inside a
galaxy hundreds of millions of light years from Earth.
They found an ultramassive black hole, an object over 30 billion times the
mass of our sun, in the foreground galaxy—a scale rarely seen by
astronomers.
This is the first black hole found using the technique, whereby the team
simulates light traveling through the universe hundreds of thousands of
times. Each simulation includes a different mass black hole, changing
light's journey to Earth.
When the researchers included an ultramassive black hole in one of their
simulations the path taken by the light from the faraway galaxy to reach
Earth matched the path seen in real images captured by the Hubble Space
Telescope.
The findings are published today in the journal Monthly Notices of the Royal
Astronomical Society.
A video showing how Astronomers used gravitational lensing to discover a
black hole 30 billion times the mass of the sun in a galaxy 2 billion light
years away. Credit: Durham University
Lead author Dr. James Nightingale, Department of Physics, Durham University,
said, "This particular black hole, which is roughly 30 billion times the
mass of our sun, is one of the biggest ever detected and on the upper limit
of how large we believe black holes can theoretically become, so it is an
extremely exciting discovery."
A gravitational lens occurs when the gravitational field of a foreground
galaxy appears to bend the light of a background galaxy, meaning that we
observe it more than once.
Like a real lens, this also magnifies the background galaxy, allowing
scientists to study it in enhanced detail.
Dr. Nightingale said, "Most of the biggest black holes that we know about
are in an active state, where matter pulled in close to the black hole heats
up and releases energy in the form of light, X-rays, and other radiation."
"However, gravitational lensing makes it possible to study inactive black
holes, something not currently possible in distant galaxies. This approach
could let us detect many more black holes beyond our local universe and
reveal how these exotic objects evolved further back in cosmic time."
The study, which also includes Germany's Max Planck Institute, opens up the
tantalizing possibility that astronomers can discover far more inactive and
ultramassive black holes than previously thought, and investigate how they
grew so large.
The story of this particular discovery started back in 2004 when fellow
Durham University astronomer, Professor Alastair Edge, noticed a giant arc
of a gravitational lens when reviewing images of a galaxy survey.
Fast forward 19 years and with the help of some extremely high-resolution
images from NASA's Hubble telescope and the DiRAC COSMA8 supercomputer
facilities at Durham University, Dr. Nightingale and his team were able to
revisit this and explore it further.
The team hopes that this is the first step in enabling a deeper exploration
of the mysteries of black holes, and that future large-scale telescopes will
help astronomers study even more distant black holes to learn more about
their size and scale.
Reference:
James Nightingale et al, Abell 1201: Detection of an Ultramassive Black Hole
in a Strong Gravitational Lens, Monthly Notices of the Royal Astronomical
Society (2023).
DOI: 10.1093/mnras/stad587
Tags:
Space & Astrophysics