Astronomers have seen two record-breaking jets of plasma blasting out of a supermassive black hole and into the void beyond its host galaxy.
The enormously powerful plasma streams are the largest ever seen, measuring 23m light-years from end to end, a distance that would cross 140 Milky Ways lined up side by side.
Researchers named the spectacular pair of jets Porphyrion after a giant in Greek mythology. The fierce, narrow streams emerge from the top and bottom of the supermassive black hole and have a combined power output equivalent to trillions of suns.
Black hole jets are streams of charged ions, electrons and other particles. It is accelerated to almost the speed of light by the immense magnetic fields around black holes. Such jets have been known for more than a century, but until recently they were thought to be rare and not that extensive.
Porphyrion was spotted by Europa’s Low-Frequency Array (Lofar) telescope during a sky survey that discovered more than 10,000 giant black hole jets. Many are so powerful that they push far beyond the black hole’s host galaxy and deep into the vast voids of the cosmic web, the network of matter that connects galaxies.
Given the size of Porphyrion, astronomers now suspect that such giant jets play a role in shaping the evolution of the universe. Black hole jets can extinguish star formation, but also inject large amounts of material and energy deep into space.
“Porphyrion shows that small things and big things in the universe are intimately connected,” said Dr Martijn Oei, a postdoctoral researcher at Caltech in the US and lead author of A Nature paper reporting the discovery. “We see a single black hole producing a structure of a scale similar to that of cosmic filaments and voids.”
After spotting Porphyrion, the researchers, including Martin Hardcastle, a professor of astrophysics at the University of Hertfordshire, used the Giant Metrewave Radio Telescope in India and the WM Keck Observatory in Hawaii to locate it within a galaxy which is 10 times larger than the Milky Way. and about 7.5 billion light years from Earth.
The Porphyrion jets began forming when the universe was about 6.3 billion years old, less than half its current age, with the jets taking a billion years to grow to their observed length, the researchers believe.
“More Porphyrion-like black hole jet systems could have existed in the past and together they could have a major impact on the cosmic web by affecting the formation of galaxies, heating the medium in the filaments, and it could also cosmic void magnetizes,” said Oei. “That’s where we want to go now.”
