The light of P172+18, a recently discovered quasar, comes from just 780 million years after the Big Bang. It's one of the most distant objects ever observed, a fact that already makes it pretty exciting. But the truly incredible thing is that astronomers also saw the hallmarks of a radio jet. At 13 billion light-years away, this is the furthest anyone has witnessed such a cosmic phenomenon.
Quasars are galaxies whose supermassive black holes are incredibly active. These black holes are caught in a feeding frenzy, and the material that is being gobbled up reaches incredible temperatures. Lots of energy is released in this process, making these supermassive black holes brighter than the galaxy around them, and allowing astronomers to spot them despite their distance.
But, as researchers report in The Astrophysical Journal, P172+18 is not your typical quasar. It is among the one-in-10 quasars that are “radio-loud,” meaning they produce a cosmic jet that shines brightly at radio frequencies. It has a supermassive black hole weighing 300 million times the mass of the Sun that is consuming gas at an incredible rate and its jet is only 1,000 years old.
“As soon as we got the data, we inspected it by eye, and we knew immediately that we had discovered the most distant radio-loud quasar known so far,” said co-lead author Eduardo Bañados from the Max Planck Institute for Astronomy in a statement.
These observations not only show one of the earliest examples of such a celestial event in the history of the universe but astronomers caught it right at its birth: An incredible find to help our understanding of the evolution of supermassive black holes and galaxies in the cosmos.
"The black hole is eating up matter very rapidly, growing in mass at one of the highest rates ever observed," co-lead author Chiara Mazzucchelli, a fellow at the European Southern Observatory (ESO) in Chile, added.
The discovery of the jet is very important. We don’t know for sure how supermassive black holes grew so big so quickly after the Big Bang. Jets might be among the mechanisms that help with their incredible growth spurt. It's thought that jets can disturb the gas around a black hole, increasing the rate material falls in. Jets also play a role in the growth of galaxies, their star-formation rate, and they throw material into intergalactic space.
Quasars are also useful to study the material between us and them. "Distant radio-emitting quasars at the beginning of the evolution of the cosmos also serve as beacons to study material that lies between Earth and the quasars," explained Bañados in a separate statement. Their emissions can be used as a backlight to illuminate the tenuous material around galaxies.
Future observatories, such as ESO’s Extremely Large Telescope, are likely to reveal that P172+18 is far from alone in having radio jets so early in the history of the universe.