This galaxy hides the closest pair of supermassive black holes to Earth
The galaxy NGC 7727 was born from the merger of two galaxies which began about a billion years ago.
Here is the galaxy NGC 7727 as observed by the Very Large Telescope (TGT) of the European Southern Observatory (ESO) installed in Chile.
This galaxy was born from the fusion of two galaxies, an event that began about a billion years ago.
It hides at its center two of the closest supermassive black holes ever discovered. The two celestial objects are spiraling closer together and will merge within 250 million years to form an even more massive black hole.
Close-up view of NGC 7727's two glowing galactic nuclei, each housing a supermassive black hole.
It is not uncommon for galaxies to enter a cosmic dance and end up merging. Our Milky Way and its neighbor Andromeda will meet this fate in about 4.5 billion years, work carried out using data collected by the European satellite Gaia shows.
In a galactic collision, individual stars usually do not collide because the distances between them remain very large on a cosmic scale.
But the gravity of two galaxies dancing between them creates tidal forces that dramatically change the appearance of both partners. Thus, it is possible to see tails of stars, gas and dust spinning around them as they eventually form a new merged galaxy.
It is this disorderly and asymmetrical shape that can be observed, a consequence of the cosmic shock that created NGC 7727.
The image published by ESO was obtained using the TGT's FORS2 (FOcal Reducer and low dispersion Spectrograph 2) instrument.
While the galaxy had already been Photographed by another ESO telescope, this new image shows more intricate detail both in the galaxy's main body and in the faint tails surrounding it, ESO notes in a statement.
In the image, you can see the tangled trails created when the two galaxies merged, stripping each other of stars and dust to create the dramatic long arms that surround NGC 7727. Parts of these arms are dotted with stars, which appear here as bright blue-purple dots.
It is highly likely that the galaxy that will result from the merger of our Milky Way and Andromeda will look like NGC 7727.
- No less than 2000 billion galaxies populate the Universe, according to estimates by British astrophysicists.
- Black holes are celestial objects that possess extremely large mass in a very small volume and whose gravitational field strength prevents any form of matter or radiation from escaping.
- There are four types black holes, including supermassives, which are found at the center of most galaxies, and stellar black holes, which are formed during the gravitational collapse of certain massive stars at the end of their lives that explode as a supernova.
The presence of two bright spots at the center of the galaxy is another clue to the galaxy's checkered past. NGC 7727's core is still made up of the original two galactic nuclei, each of which harbors a supermassive black hole, ESO adds.
These black holes are located at approximately 89 million light-years from Earth, in the constellation Aquarius. This is the pair of black holes closest to our planet. Furthermore, they are only 1600 light years away in the sky. When they merge, they will form an even more massive black hole.
The arrival of ESO's European Giant Telescope in 2025 should make it possible to study the pairs of hidden supermassive black holes and could lead to new discoveries.