A team of astronomers from theArc Center of Excellence for All Sky Astrophysics in 3 Dimensions has immortalized the image of a very rare particular galaxy that looks like a cosmic ring of fire. The galaxy, called R5519, is approx 11 billion light years from the Solar System it has a mass similar to that of the Milky Way and a circular shape with a hole in the middle. His discovery, announced in a study published on Nature Astronomy, could change the theories about the first formation of galactic structures and their evolution.
R5519 boasts interesting features for astronomers: the hole in the center, for example, is really huge with a diameter two billion times larger than the Earth-Sun distance. In other words, it is three million times larger than the diameter of the supermassive black hole in the center of the galaxy Messier 87, the first to be immortalized in 2019 by the Event Horizon Telescope.
“The galaxy is accumulating a large amount of stars at a rate of speed 50 times faster than that of the Milky Way – says Tiantian Yuan, author of the study – most of this activity is taking place on its ring and therefore it is correct to define it as fire”. Arc astronomers collaborated with colleagues from the United States, Canada, Belgium and Denmark, using spectroscopic data from theKeck observatory of Hawaii together with images collected by the space telescope Hubble, which identified the unusual structure of the galaxy.
The data show that we are facing one collision ring galaxy, the first to have been located in the primordial universe, which would have formed due to the violent collision with other galaxies. Astronomers believe that studying such an object can tell us a lot about the formation process of spiral galaxies.
“The collisional formation of ring galaxies requires that a thin disk is present in the ‘victim’ galaxy before the collision occurs – concludes Kenneth Freeman of the Australian National University – the thin disk is the component that defines spiral galaxies: during early stages of development galaxies are in a disordered state, not yet recognizable as spiral galaxies. In the case of R5519 we are looking back into the primordial universe of 11 billion years, at a time when thin disks were just assembling. To make a comparison, the disk of our Milky Way began the training process only 9 billion years ago. This discovery indicates that disk assembly in spiral galaxies occurred for a longer period than previously known. “