If you peer billions of years across time and space, you will see “quasars,” enormously energetic galactic cores, powered by supermassive black holes, that are brighter than any other object in the universe.
Now, scientists led by Feige Wang, an NHFP Hubble Fellow at the University of Arizona, have discovered “the most distant quasar yet known,” according to a forthcoming study in The Astrophysical Journal Letters (a copy is available on the preprint server arXiv).
The quasar was spotted in the early universe, just 670 million years after the Big Bang. This glimpse of a radiant ancient relic across such vast distances and epochs challenges our assumptions about the evolution of supermassive black holes and the galaxies that host them in their cores.
The quasar’s central supermassive black hole, which clocks in at about 1.6 billion times the mass of the Sun, is surrounded by infalling stars and gas. The intense tidal forces that the black hole exerts on this material creates explosive outflows of ultra-luminous and superheated material that are being shot into deep space at up to 20 percent the speed of light.
Brilliant quasars have previously been discovered at these “high redshifts,” a term that refers to the apparent reddening of light waves across long distances. For that reason, Wang said in an email that the detection of the most distant quasar on record was “not a surprise” though he still called it “a very exciting discovery.”
“We have been hunting for these distant quasars in the past several years,” said Wang, who presented the new findings during a Tuesday press conference at the 237th meeting of the American Astronomical Society, which is being held virtually due to the coronavirus pandemic.
“Based on our understanding of distant quasars, we would expect there are a couple of quasars with similar luminosity that could be found at such a high redshift from the whole observable universe,” he added. “But the massive black hole in the center and the existence of extremely high velocity outflow (quasar wind) at a speed up to 20 percent of the speed of light is a bit of a surprise to me.”
Most black holes are forged from the explosion and collapse of huge stars; these objects may then form ever-larger supermassive black holes by merging with each other. But the newly discovered quasar, named J0313- 1806, is so immense that scientists aren’t sure how it could have coalesced so quickly in the early universe.
Wang and his colleagues first identified the quasar in data collected by Pan-STARRS1 and the UKIRT Hemisphere Survey, and then followed up with high-precision observations captured by the Keck Observatory and Gemini North atop Hawaii’s Mauna Kea.
Because of its enormous energy output and unrivaled distance, J0313–1806 “is an ideal target for investigating the assembly of the earliest [supermassive black holes] and their massive host galaxies” with future high-resolution observations, according to the study.
“Our current observations are limited by the spatial resolution and the sensitivity,” Wang explained. “We really need the upcoming James Webb Space Telescope (JWST) to give a more detailed investigation of the assembly of the [supermassive black hole] and its host galaxy.”
Currently due for launch in October, JWST will be about 100 times more sensitive than the Hubble Space Telescope, and will also provide three-dimension information—called integral field spectroscopy (IFS)—about distant objects such as J0313–1806.
“The IFS observations from JWST will allow us to map the kinematic motion of gas in the quasar host galaxy and the gas from the quasar outflow” which will “provide more clues about how those gases are interacting with each other, how the outflow is affecting the star formation in the quasar host galaxy, and how the gas is feeding the central black hole,” Wang said.
Not only will this reveal new secrets about this specific quasar and its gargantuan black hole, it could also shed light on some of the broader mysteries of the universe’s infancy.
“One important thing we did not mention too much is that such distant quasars could be used to study cosmic reionization, the last major transition phase of our universe,” Wang said.
“It can also help us to understand how the metal (elements heavier than helium) were produced in the early universe,” he concluded.