That means it is three million times bigger than the diameter of the supermassive black hole in the galaxy Messier 87, which in 2019 became the first ever to be directly imaged.
Astronomers have captured an image of this "cosmic ring of fire" as it existed 11 billion years ago. It was roughly the mass of the Milky Way, is circular with a hole in the middle, rather like a titanic doughnut.
Graphical representation of R5519. Credit: James Josephides, Swinburne Astronomy Productions
There are two kinds of ring galaxies. The more common type forms because of internal processes. Collisional ones form - as the name suggests - as a result of immense and violent encounters with other galaxies. In the nearby "local" Universe they are 1000 times rarer than the internally created type. Images of the much more distant R5519 stem from about 10.8 billion years ago, just three billion years after the Big Bang. They indicate that collisional ring galaxies have always been extremely uncommon. The astronomers used used spectroscopic data gathered by the WM Keck Observatory in Hawaii and images recorded by NASA's Hubble Space Telescope to identify the unusual structure; the first "collisional ring galaxy" in the early Universe.
Co-author Professor Kenneth Freeman from the Australian National University, said the discovery had implications for understanding how galaxies like the Milky Way formed. "The collisional formation of ring galaxies requires a thin disk to be present in the 'victim' galaxy before the collision occurs. The thin disk is the defining component of spiral galaxies: before it assembled, the galaxies were in a disorderly state, not yet recognisable as spiral galaxies.
"In the case of this ring galaxy, we are looking back into the early universe by 11 billion years, into a time when thin disks were only just assembling. For comparison, the thin disk of our Milky Way began to come together only about nine billion years ago. This discovery is an indication that disk assembly in spiral galaxies occurred over a more extended period than previously thought."