US, WASHINGTON (ORDO NEWS) — Astronomers have discovered the greatest rarity: a galaxy in the form of a ring. Such an object has never been found in such an early Universe. Experts believe that the cosmic cataclysm that happened at the dawn of time gave an unusual form to the star system.
The achievement is described in a scientific article published in the journal Nature Astronomy.
Galaxy R5519 has the shape of a ring surrounded by a diffuse halo. At its center is a void with a diameter of 30 thousand light years (this is about a third of the diameter of the Milky Way). Because of this, the radius of the ring galaxy is 1.5-2.2 times larger than that of the Milky Way, with almost the same mass.
But in the ring itself, matter is located very densely. Therefore, luminaries are intensively born here.
“It (the galaxy R5519 – Ed.). Creates the stars 50 times faster than the Milky Way, – says the first author of the article Tiantian Yuan ( Tiantian Yuan ) from Swinburne University of Technology -. For the most part, this process takes place in the ring, so that it really is a ring of fire.”
There are various reasons why a galaxy can take such an unusual shape. But in this case, experts are sure that the matter is in a space cataclysm.
Once upon a time, another galaxy collided with R5519. An uninvited guest, like a cannonball, flew through the very center of the “target”. This event generated waves similar to circles on the water. They took the substance with them, and a round hole formed in the center of the affected star system. So the R5519 turned into a ring or, if you like, into a bagel.
In this scenario, experts are convinced by several facts. First, this is evidenced by the speed of rotation of the star system at the boundary of the ring. Secondly, an extended diffused stellar halo is also a typical sign of a long-standing catastrophe. Finally, next to the R5519 is a small star system, which probably once pierced it through.
Galaxies that have become circular as a result of such a cataclysm are a huge rarity. In the environs of the Milky Way closest to cosmological standards, only about 0.01% of all star systems survived such a blow.
But the R5519 is unique not only for this. The fact is that the light from it reaches the Earth in 10.8 billion years. This means that now we see it as it was when the age of the universe was less than 15% of the current one.
That is, this system gave scientists the first evidence that collisions with the formation of ring-shaped galaxies have already occurred in such ancient times.
Why is it important? The fact is that a collision makes a galaxy bagel only if it has already formed a thin disk .
“A thin disk is a defining component of spiral galaxies: prior to its formation, the galaxy is in a chaotic state that is not yet recognized as a spiral galaxy,” explains co-author Kenneth Freeman of Australian National University.
It turns out that the R5519 thin disk already existed 10.8 billion years ago. Meanwhile, it is believed that in the Milky Way it began to form only 9 billion years ago (although recent discoveries show that some of its stars are much older ).
Contact us: [email protected]