NGC 6240
Photo of the NGC 6240 galaxy. NASA/ESA Hubble Space Telescope

For the first time, a team of astronomers was able to uncover a galaxy that is inhabited by three supermassive black holes. The galaxy was previously thought to have been formed by a colossal merger between two galaxies.

The galaxy spotted by the astronomers is known as NGC 6240. It is located in the constellation Ophiuchus and is about 400 million light-years from Earth’s neighborhood. Previous observations conducted on the galaxy showed traces of a massive merger between two large cosmic bodies.

According to studies, the collision and merger of two galaxies disrupted the overall structure of NGC 6240.

In a new study, astronomers from Germany revisited NGC 6240 using the European Southern Observatory’s Very Large Telescope and the 3D MUSE Spectrograph, which uses visible light to observe distant cosmic objects.

With these tools, the astronomers were able to get a closer look at NGC 6240. To their surprise, they discovered three supermassive black holes within the galaxy’s center. According to the astronomers, this strongly indicates that NGC 6240 was formed by three galaxy mergers, not two as previously thought.

“Through our observations with extremely high spatial resolution we were able to show that the interacting galaxy system NGC 6240 hosts not two – as previously assumed – but three supermassive black holes in its center,” Wolfram Kollatschny, a professor at the University of Göttingen and lead author of the study, said in a press release.

According to Kollatschny and his colleagues, their discovery marks the first time that three supermassive black holes were spotted in a galaxy that was formed by triple mergers. The astronomers noted that their discovery could shed new light on the formation of galaxies, especially those that are exceptionally massive.

“If, however, simultaneous merging processes of several galaxies took place, then the largest galaxies with their central supermassive black holes were able to evolve much faster,” the study’s co-author Peter Weilbacher of the Leibniz Institute for Astrophysics Potsdam explained. “Our observations provide the first indication of this scenario.”

The findings of the astronomers regarding NGC 6420’s triple merger and supermassive black holes were presented in a new study published in the journal Astronomy and Astrophysics.