A team of astronomers has discovered one of the largest black holes ever discovered, taking advantage of a phenomenon called gravitational lensing.
Curvilinear gravity of light
The team, led by Durham University in the UK, used gravitational lensing – where a foreground galaxy bends and magnifies light from a distant object – and supercomputer simulations at the DiRAC HPC facility enabled the team to closely examine how light is bent by a black hole inside a galaxy hundreds of miles away. Millions of light years from Earth.
The team simulated light traveling through the universe hundreds of thousands of times, with each simulation involving a different mass[{” attribute=””>black hole, changing light’s journey to Earth.
30 billion times the mass of our Sun
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.
What the team had found was 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 gravitational lensing and the findings were published today (March 29) 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
Looking back in cosmic time
Most of the largest black holes we know of are in an active state, as matter being pulled near the black hole heats up and releases energy in the form of light, X-rays, and other radiation.
Gravitational lensing makes it possible to study inactive black holes, which is not currently possible in distant galaxies. This approach could allow astronomers to detect inactive black holes that are more massive than previously thought and investigate how they grow so massive.
The story of this very discovery began in 2004 when fellow Durham University astronomer Professor Alastair Edge noticed a giant arc of a gravitational lens when reviewing SGS images.
Fast forward 19 years and with the help of some very high resolution photos from[{” attribute=””>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.
Exploring the mysteries of black holes
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: “Abell 1201: detection of an ultramassive black hole in a strong gravitational lens” by J W Nightingale, Russell J Smith, Qiuhan He, Conor M O’Riordan, Jacob A Kegerreis, Aristeidis Amvrosiadis, Alastair C Edge, Amy Etherington, Richard G Hayes, Ash Kelly, John R Lucey and Richard J Massey, 29 March 2023, Monthly Notices of the Royal Astronomical Society.
DOI: 10.1093/mnras/stad587
The research was supported by the UK Space Agency, the Royal Society, the Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI), and the European Research Council.
This work used both the DiRAC Data Intensive Service (CSD3) and the DiRAC Memory Intensive Service (COSMA8), hosted by University of Cambridge and Durham University on behalf of the DiRAC High-Performance Computing facility.
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