A team of astronomers has observed pairs of supermassive black holes at the messy core of merging galaxies.
The research team looked through the thick walls of gas and dust in the messy cores of the merging galaxies. They found pairs of supermassive black holes occupying the centres of one of the two smaller galaxies as they merged together into one giant black hole.
Observing merging galaxies
Michael Koss, a research scientist at Eureka Scientific Inc, said: “Seeing the pairs of merging galaxy nuclei associated with these huge black holes so close together was pretty amazing…In our study, we see two galaxy nuclei right when the images were taken. You can’t argue with it; it’s a very ‘clean’ result, which doesn’t rely on interpretation.”
Richard Mushtotsky, a professor of astronomy at UMD and a fellow of the Joint Space-Science Institute (JSI), discussed how using Swift’s BAT allowed them to see the supermassive black holes at the core of the merging galaxies. He said: “The advantage to using Swift’s BAT is that it observes high-energy, ‘hard’ X-rays. These X-rays penetrate through the thick clouds of dust and gas that surround active galaxies, allowing the BAT to see things that are literally invisible in other wavelengths.”
The significance of the supermassive black holes
The high-resolution images taken by the astronomers give a close-up view of a phenomenon that astronomers believe was more common in the early universe. When black holes collide, they unleash powerful gravitational waves.
Laura Blecha, an assistant professor of physics at the University of Florida and a co-author of the study, commented:”The fact that black holes grow faster and faster as mergers progress tells us galaxy encounters are really important for our understanding of how these objects got to be so monstrously big.”
According to the University of Maryland, the images also offer a preview of a likely scenario in a few billion years, when our Milky Way galaxy merges with the neighbouring Andromeda galaxy.
Both galaxies host supermassive black holes at their core and eventually they will merge together into one larger black hole.