An international team of astronomers has just made public the discovery of one of the largest black holes observed so far, a ‘space beast’ 30,000 million times more massive than the Sun. The finding, published in ‘Monthly Notices of the Royal Astronomical Society ‘, was made possible by combining the use of gravitational lensing with computer simulations at the DiRAC HPC facility at Durham University, UK.
The team, in fact, used that well-known optical phenomenon, in which a foreground galaxy bends light from a more distant object and magnifies it, much like a cosmic magnifying glass. In this way, the researchers measured the deflection of light from a galaxy hundreds of millions of light-years from Earth and then entered the data into the computer. The next step was to perform hundreds of thousands of simulations of that light traveling through the Universe.
In each of them, the team included a black hole of different mass, until they found the one that coincided with what was shown by the gravitational lens, obtained with the Hubble Space Telescope. The result was that, in the center of that distant galaxy, sleeps a ‘monster’ with a mass equivalent to that of 30,000 million suns, which becomes in its own right one of the largest black holes observed in the entire history of the astronomy. It is also the first black hole found using this technique.
In the words of James Nightingale of the University of Durham and lead author of the paper, “This particular black hole, which is approximately 30 billion times the mass of our Sun, is one of the largest ever detected and is in the upper limit of how big we think, theoretically, black holes can get, so it’s an extremely exciting discovery.”
“Most of the largest black holes that we know of – continues the researcher – are in an active state, where the matter that approaches 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 as well, something that is currently not possible in distant galaxies. This approach could allow us to detect many more black holes beyond our local universe and reveal how these exotic objects evolved further back in cosmic time.”
A history of two decades
The story of this discovery began in 2004, when astronomer Alastair Edge, Nightingale’s University of Durham colleague, noticed the giant arc of gravitational lensing while reviewing images from a galaxy survey. Today, 19 years later, and with the help of new, very high-resolution images from Hubble and the University’s supercomputer, Nightingale and his team were able to further explore the region and make their sensational discovery.
The researchers hope that this is just a first step in exploring deeper into the mysteries of black holes, and that future telescopes will help astronomers study even the most distant of these obscure objects to learn more about their size and scale. .
Black holes, it must not be forgotten, are closely related to the history and evolution of the galaxies that contain them, which probably would not exist without them.