Scientists using the Hubble Space Telescope to study distant quasars – the brightest objects in the universe – have captured a rare image that raises new questions about how they form.

Quasars can reach luminosities thousands of times brighter than the Milky Way. They are caused by supermassive black holes at the cores of distant galaxies consuming vast amounts of material, which heats up and is blasted out in massive jets.

These jets are thought to be triggered by major galaxy mergers, which funnel gas toward the black hole and disrupt any spiral formation a galaxy might have had previously. The finding that a quasar – J0742+2704 – sits at the centre of a spiral galaxy suggests there may be other pathways for jet formation.

“We typically see quasars as older galaxies that have grown very massive, along with their central black holes, after going through messy mergers and have come out with an elliptical shape,” says Astronomer Kristina Nyland of the Naval Research Laboratory says.

“It’s extremely rare and exciting to find a quasar-hosting galaxy with spiral arms and a black hole that is more than 400 million times the mass of the Sun — which is pretty big — plus young jets that weren’t detectable 20 years ago.” Quasar J0742+2704 was discovered to have a newborn jet in 2020.

While quasar J0742+2704’s doesn’t appear to have experienced a major disruptive galaxy merger, the Hubble image does reveal a distortion in one of its arms – a tidal tail, or streamer of gas, pulled out by the gravity of a nearby galaxy.

“Clearly there is something interesting going on,” says Nyland. “It may be interacting with another galaxy, which is gravitationally tugging at its spiral arm.”

Another clue is the presence of a large galaxy to the lower right of the quasar in the Hubble image, which appears to be a ring galaxy. This distinctive shape is thought to form when a small galaxy passes through the centre of a large one.

“The ring galaxy near the quasar host galaxy could be an intriguing clue as to what is happening in this system. We may be witnessing the aftermath of the interaction that triggered this young quasar jet,” said Nyland.

The researchers will carry out further analysis of Hubble’s data and follow-up with other telescopes to confirm the distances of the galaxies and how they may be affecting one another.