Deep in the universe's past, astronomers have discovered a luminous quasar powered by an enormous black hole that contains the mass of 12 billion suns. The incredibly bright object is ancient -- shining when the universe was only 875 million years old -- and way bigger than it should be for an object its age.
The unusual quasar, described Wednesday in the journal Nature, is the biggest and brightest one known to have formed within 1 billion years of the Big Bang. The find could cause researchers to alter their understanding of how such super-massive black holes form -- and shed light (literally) on the conditions in the early universe.
The quasar, named J010013.02+280225.8, or J0100+2802 for short, is powered by a massive black hole that's pulling in so much stuff that the material accelerating toward it produces an incredible amount of light. There are about 40 known quasars spotted within a billion years of the Big Bang, and they weigh in around a billion solar masses. Compared with its peers, this quasar is a monster -- by far the biggest and the brightest.
“We were surprised,” said study coauthor Xiaohui Fan, an astronomer with the Steward Observatory at the
Fan and his colleagues discovered J0100+2802 while looking through data from the Sloan Digital Sky Survey, which has logged more than 500 million objects in the northern skies. This object was very red -- a sign that its wavelengths of light had been stretched over a long journey through space and time -- and exceptionally luminous.
"We're not used to looking at objects that bright because when we think about these quasars as distant objects, they're supposed to be very faint," Fan said. So the team followed up on the quasar using a number of other telescopes.
It's thought that nearly every massive galaxy has a black hole at its center. Our galaxy, the Milky Way, certainly does -- its central singularity weighs in at about 4 million to 5 million solar masses (far less than a thousandth the size of J0100+2802). Such super-massive black holes are thought to have grown from initial seeds with a mere 100 to 100,000 suns' worth of stuff to the behemoths we see today.
But black holes can take billions of years to grow. And yet, this enormous quasar rivals the biggest black holes of today even though it existed just 875 million years after the Big Bang, or about 6% of the universe's current age.
Here's how a quasar works: The material falling toward a powerful black hole heats up as it accelerates and produces an overwhelming amount of light. All of this radiation pressure pushes back other material falling into the black hole, which should slow the accumulation rate somewhat, according to Bram Venemans of the Max Planck Institute for Astronomy in Germany, who wrote a commentary on the study.
But given its massive size, this quasar seems to be ignoring that convention.
"The fact that the supermassive black hole has grown to 12 billion solar masses in less than a billion years implies that the radiation did not inhibit the high accretion," Venemans wrote. Understanding why that is could help scientists refine their understanding of black hole dynamics.
The researchers also want to study the galaxy housing this black hole, to see if it follows or breaks galactic convention (for example, the bigger the black hole, the bigger the galaxy).
This incredibly bright quasar could also offer a fresh window onto the early universe, Venemans wrote. As the quasar's light passes through the gas of the intergalactic medium, the stuff in the gas -- hydrogen, helium and other elements -- leaves an imprint on the light's fingerprint. Scientists can read this fingerprint to learn about the abundance of different elements in the universe's early history.
"The quasar can therefore be used as a means of learning about the distant cosmos. ... The brighter the quasar, the more comprehensive the investigation of the intervening gas can be," Venemans wrote.