Skip to main content

Pairs of supermassive black holes spotted in colliding galaxies

We know that our universe is full of black holes, existing everywhere from between ancient strange clusters of stars to the massive black hole at the center of the Milky Way. Now astronomers from the Swiss Federal Institute of Technology (ETH) in Zurich have discovered several pairs of supermassive black holes located at the center of galaxies which are colliding together.

The scientists were examining what happens when two galaxies merge together into one larger galaxy. The process of collision generates huge amounts of gas and dust around the cores of the galaxies, which makes it difficult to see what is happening within. But the scientists were able to identify two supermassive black holes at the center of the two original galaxies which are drawing closer together and which will eventually coalesce into one enormous black hole.

Recommended Videos

The team used images from the W.M. Keck Observatory in Hawaii and NASA’s Hubble Space Telescope to survey nearby galaxies and to find pairs of galaxies which were merging. In total, they looked at 385 galaxies from the archive of Hubble images and 96 galaxies from the Keck telescope. Using Hubble images, they were able to identify galaxy NGC 6240, whose two cores have nearly melded and which could be seen through infrared light which pierces the dust and gas around the central core. Four other merging galaxies were also discovered from the Keck Observatory data, which used near-infrared light and adaptive optics to identify merging galaxies.

Overall, the findings suggest that more than 17% of the galaxies that they studied had a pair of black holes at their center which were spiraling closer and closer together. Eventually, all of these pairs of black holes will come together to form an even larger black hole, which should happen in the next 10 million years. That might sound like a long time, but in cosmic terms it’s very soon.

“This is the first large systematic survey of 500 galaxies that really isolated these hidden late-stage black hole mergers that are heavily obscured and highly luminous,” lead researcher Dr. Michael Koss told Science News. “It’s the first time this population has really been discovered. We found a surprising number of supermassive black holes growing larger and faster in the final stages of galaxy mergers.”

The findings are published in Nature.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Stunning image shows the magnetic fields of our galaxy’s supermassive black hole
The Event Horizon Telescope (EHT) collaboration, who produced the first ever image of our Milky Way black hole released in 2022, has captured a new view of the massive object at the center of our Galaxy: how it looks in polarized light. This is the first time astronomers have been able to measure polarization, a signature of magnetic fields, this close to the edge of Sagittarius A*. This image shows the polarized view of the Milky Way black hole. The lines mark the orientation of polarization, which is related to the magnetic field around the shadow of the black hole.

The Event Horizon Telescope collaboration, the group that took the historic first-ever image of a black hole, is back with a new stunning black hole image. This one shows the magnetic fields twirling around the supermassive black hole at the heart of our galaxy, Sagittarius A*.

Black holes are hard to image because they swallow anything that comes close to them, even light, due to their immensely powerful gravity. However, that doesn't mean they are invisible. The black hole itself can't be seen, but the swirling matter around the event horizon's edges glows brightly enough to be imaged. This new image takes advantage of a feature of light called polarization, revealing the powerful magnetic fields that twirl around the enormous black hole.

Read more
Nightmare black hole is the brightest object in the universe
Artist’s impression showing the record-breaking quasar J059-4351.

A  recently discovered monster black hole feasts on so much nearby material that it's the fastest-growing of its kind on record. The beefy black hole is devouring the equivalent mass of our sun every single day, making it a record-breaker in more ways than one.

“The incredible rate of growth also means a huge release of light and heat,” said lead researcher Christian Wolf of The Australian National University in a statement. “So, this is also the most luminous known object in the universe. It’s 500 trillion times brighter than our sun.”

Read more
Scientists want your help to search for black holes
An illustration of a black hole.

Even though black holes swallow anything that comes near them -- even light -- they are still possible to locate by looking for signs of their effects. Black holes are extremely dense, so they have a lot of mass and a strong gravitational effect that can be observed from light-years away. But the universe is a big place, and researchers are hoping that the public can help them to identify more black holes in the name of scientific exploration.

A project called Black Hole Hunter invites members of the public to search through data collected by NASA's Transiting Exoplanet Survey Satellite (TESS) to look for signs of a black hole. Using a technique called gravitational microlensing, citizen scientists will look at how the brightness of light from various stars changes over time, looking for indications that a black hole could have passed in front of a star and bent the light coming from it. This should enable the project to identify black holes that would otherwise be invisible.

Read more