Black holes are the most powerful and scary monsters in our universe, lurking at the centers of galaxies. Some, such as the black hole at the center of our own Milky Way Galaxy, have already finished their cosmic meals, with just occasional nibbles observed today. Others, however, are seen ravenously devouring delicious matter from their surroundings. At such times, black holes are noisy eaters, dominating all the activity in their host galaxy centers. As matter spirals in towards the bottomless maw, it collides, heats up, and becomes very bright from X-ray to infrared energies. The accretion disk around a supermassive black hole can easily outshine the billions of stars in a galaxy, and that incredible brightness can make them some of the most distant objects we can observe in both space and time. Black holes can also be messy eaters, spewing out material in cosmic jets that can reach thousands and even millions of light years from the black hole—material that can then go on to influence the universe around it.

Of the many mysteries that keep astronomers up all night observing and pondering these enigmatic beasts, one of the most perplexing is how black holes grow to such enormous sizes. We see supermassive black holes with masses hundreds of millions of times that of the Sun, observed when the universe was only a few hundred million years old. It’s like finding 7-foot basketball players or 300-pound football players with appetites to match in a Kindergarten classroom: just how were they able to grow so big so quickly?

Recent observations by NASA’s NuSTAR and Chandra X-ray observatories might offer some clues. In a paper recently published by the Astrophysical Journal, scientists led by Lea Marcotulli at Yale University and Thomas Connor at the Center for Astrophysics | Harvard & Smithsonian report on observations of the most X-ray luminous accreting black hole, or quasar, ever discovered in the first billion years of the universe. This quasar, called CFHQS J1429+5447, was initially found 15 years ago using data from a ground-based telescope that surveyed wide patches of the sky. Far more recently it was observed by Chandra, which was able to pick up X-rays from this incredibly distant source. Only four months afterwards, NuSTAR also observed it, finding that the quasar had doubled in X-ray brightness in that time.

Such a dramatic variation in such a short time for something this massive is evidence towards this quasar being a particularly messy eater, expelling a powerful jet of material at close to the speed of light. This jet is pointed straight at Earth—a chance alignment that boosts the amount of light making its way to us, allowing telescopes in Earth's orbit like NuSTAR and Chandra to see it at such a great distance.

"These results have significant implications for supermassive black holes and jet evolution theories," said Marcotulli. "The presence of a jet may be a necessity to grow such extreme black holes so early in the Universe."

Because the light observed from this quasar was emitted when the Universe was still very young, this lets us see into an era soon after the Big Bang called the Epoch of Reionization. This time period was when light began to be able to pass through the Universe unimpeded, which is what allows us to see stars and galaxies and distant quasars today. Exactly what kind of objects helped to clear the way for light to travel through space is a mystery that astronomers are still seeking to unravel, but the discovery of a cosmic jet like this one suggests that the Universe's biggest, messiest eaters might have been involved.