A flickering source of light from the Big Bang’s aftermath may illuminate how some of the brightest black holes in the universe develop. This light emanates from a quasar — the luminous core of a galaxy, powered by a supermassive black hole — that originated just 850 million years after the universe was born.
A new study published in Nature Astronomy has detailed the detection of the earliest known flickering quasar, which is estimated to be as bright as 12 trillion suns, according to a press statement. But beyond its staggering brightness, astronomers are far more interested in its flicker, which has shown that the quasar is shockingly stable. The quasar’s accretion disk is flat and pancake-like and not as turbulent as early black holes are expected to be, raising questions about when black holes evolve from chaotic to calm.
“I think what this suggests is that all the messy, very rapid growth phases that we expect all black holes to go through at some point happen very, very early on, before we see them as these very bright luminous quasars,” said study author Anna-Christina Eilers, an assistant professor of physics at MIT, in the statement. “That’s the picture that’s emerging.”
Read More: When Black Holes Die, They Are Reborn As White Holes
Tracing an Early Quasar's Flicker
Flickering from a quasar can be traced to gather details on the shape and structure of the earliest supermassive black holes in the universe, but this isn't an easy task. Light gets stretched out the older it is in the universe, meaning that any observable flickers would be spaced out over a long period of time. For example, a flicker that naturally occurs over several weeks would look as if it were flickering only every few months when viewed from billions of light-years away.
Despite the difficulties in tracing flickering quasars, researchers managed to spot a flicker in archival data from NASA’s 14-year-long sky-scanning mission, NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer). The flicker came from the cosmic dawn, the period when the first stars, black holes, and galaxies were beginning to develop.
“We saw the quasar flickering randomly over the 14-year period, much like a candle’s flame flickers without a fixed pattern,” said study author Gene Leung, a postdoctoral researcher at MIT, in the statement.
“Although there have been a lot of quasars found in the cosmic dawn, this is the first time we actually see one flickering,” Leung added.
Quick to Calm Down
The researchers tracked the flicker in different wavelengths, deciphering the shape of its accretion disk (the whirlpool of gas and dust swirling around a supermassive black hole). They were able to determine that the disk was flat; this shape, oddly enough, normally belongs to nearby black holes that are stable. Black holes that formed early in the universe are expected to have a more puffy accretion disk, representing a more chaotic system forged in the early stages of black hole development.
The researchers say that the quasar flicker from 850 million years after the Big Bang suggests that supermassive black holes in the early universe must have grown rapidly into a mature state before adopting a less chaotic accretion disk.
“This provides direct evidence that the same feeding processes and structures observed in the nearby universe were already in place at very early times, despite very different cosmic environments, which had never been seen before,” said Eilers.
The Search for Supermassive Black Holes
Astronomers have found more than 200 supermassive black holes in the universe's first billion years. These were only spotted because of the spectacular light they emit during their quasar phase. The most distant quasar known to science, observed just 670 million years after the Big Bang in 2021, was found to be 10 trillion times as luminous as our sun, according to the Gemini Observatory.
The researchers involved with the new study want to look for an even earlier stage in a quasar's development in the hope that it could reveal how the first supermassive black holes were forged.
Read More: Black Holes May Hint at the Universe Being a Hologram — but Is It True?
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a study published in Nature Astronomy: Discovery of quasar variability and early accretion disk signatures at cosmic dawn
- This article references information from the Gemini Observatory: The Earliest Supermassive Black Hole and Quasar in the Universe
