The first-ever photograph of a black hole – a ring of fire of light surrounding a black hole of emptiness – stunned the world three years ago. The Event Horizon Telescope, a global network of synchronized radio plates serving as one large telescope, has brought this image of the black hole at the center of the Messier 87 galaxy into focus. more convenient. With this new development, astronomers may be able to study black holes smaller than Messier 87 in more distant galaxies.
There are only two criteria for this approach. For starters, there must be a pair of merging supermassive black holes. Second, this pair must be approached from an almost lateral angle. From this point on, one should be able to observe a bright flash while one black hole passes in front of another. The luminous ring of the black hole is further magnified by the black hole closest to the observer, a phenomenon known as gravitational lenses.
The effect of lenses is well known, but researchers have found a hidden signal in this case: a clear decrease in brightness, corresponding to the shadow of the black hole in the background. Depending on how huge the black holes are and how closely their orbits are connected, this slight eclipse can last from a few hours to a few days.
The study was published in the journal Physical examination D.
Jordi Davelaar, PhD student in Colombia and the Center for Computational Astrophysics at the Flatiron Institute, and the first author of the study said that the high-resolution image of M87 black holes requires years and considerable effort from dozens of scientists. This method only works for the largest and closest black holes, both in the center of the M87 and probably the Milky Way.
Davelaar added that their method involves measuring the brightness of black holes over time, rather than spatially resolving each object.
Speaking about the shadow of a black hole, study co-author Zoltan Hyman said that the size of the black hole, the shape of space-time around it and how matter falls into the black hole on its horizon were revealed by this dark region. Hyman is a professor of physics in Colombia.
After discovering a putative pair of supermassive black holes in the heart of a distant galaxy in the early universe, researchers became interested in the eruption of supermassive black holes. NASA’s Kepler Space Telescope was looking for slight declines in brightness that indicate a planet is passing in front of its home star. Instead, Kepler discovered eruptions from a pair of merging black holes, according to Hyman and colleagues.
They named the distant galaxy “Spikey” for brightness jumps caused by its probable black holes, which amplify each other through the effect of lenses with each complete rotation. Hyman and Davelaar then built a model to learn more about the eruption.
Researchers are now looking for more data from the telescope to confirm the decline in Kepler’s data and to prove that Spike is indeed home to a pair of merging black holes. If all goes well, the approach could be used to confirm a number of other alleged merging pairs of supermassive black holes among the 150 or so that have been discovered so far.