Artist’s concept of Milky Way as it might have appeared 6 million years ago during a ‘quasar’ phase of activity. Image via Mark A. Garlick/CfA.
The farthest known quasar has been located more than 13 billion light years from Earth, driven by a supermassive black hole more than 1.6 billion times more massive than the Sun and more than 1,000 times brighter than our entire Milky Way.
The quasar, called J0313-1806, looks like it was when the Universe was only 670 million years old and is providing astronomers with valuable information about how massive galaxies, and supermassive black holes at their cores, formed in the early Universe. .
The new discovery, presented by its authors at the American Astronomical Society meeting and in an article in Astrophysical Journal Letters, surpasses the previous distance record for a quasar set three years ago. Observations with the Atacama LargeMillimeter / submillimeter Array (ALMA) in Chile confirmed the distance measurement with high precision.
Quasars occur when the powerful gravity of a supermassive black hole at the core of a galaxy pulls in surrounding material that forms an orbiting disk of superheated material around the black hole. The process releases enormous amounts of energy, which
makes the quasar extremely bright, often outshining the rest of the galaxy. The black hole in the core of J0313-1806 is twice as massive as that of the previous record holder and that fact provides astronomers with a valuable clue about such holes.
blacks and their effect on host galaxies.
“This is the earliest evidence of how a supermassive black hole is affecting the galaxy around it,” said Feige Wang, a Hubble member of the University of Arizona Steward Observatory and leader of the research team. the less distant galactic observations we know this has to happen, but we have never seen it so early in the Universe. “
The enormous mass of the black hole of J0313-1806 at such an early time in the history of the Universe rules out two theoretical models for how such objects formed, astronomers acknowledge. In the first of these models, individual massive stars explode as supernovae and collapse into black holes that then merge into larger black holes.
In the second, dense star clusters collapse into a huge black hole. In both cases, however, the process takes too long to produce a black hole as massive as the one in J0313-1806 at the age we see it. “This tells you that no matter what you do, the seed of this black hole must have been formed by a different mechanism,” explains Xiaohui Fan, also from the University of Arizona. “In this case, it is a mechanism that involves large quantities. of primordial cold hydrogen gas collapsing directly into a black seed hole “.
ALMA’s observations of J0313-1806 provided tantalizing details about the quasar’s host galaxy, which is forming new stars at 200 times the speed of our Milky Way. “This is a relatively high rate of star formation in galaxies of similar age, and indicates that the quasar’s host galaxy is growing very fast,” says Jinyi Yang, the second author of the report, also from the University of Arizona. The brightness of the quasar indicates that the black hole swallows the equivalent of 25 suns each year. The energy released by that fast feeding, astronomers say, is likely driving a powerful outflow of ionized gas that is seen moving at about 20 percent of the speed of light. These outflows are believed to be what ultimately stop star formation in the galaxy.
“We think those supermassive black holes were the reason why many of the large galaxies stopped forming stars at some point,” Fan explains. “We observed this ‘extinction’ in later times, but until now, we didn’t know how early. started this
process in the history of the Universe. This quasar is the earliest evidence that extinction may have been occurring in very early times. “This process will also leave the black hole with nothing to eat and stop its growth, says Fan.
In addition to ALMA, the astronomers used the 6.5-meter Magellan Baade telescope, the Gemini North telescope and the WM Keck Observatory in Hawaii, and the Gemini South telescope in Chile. Now astronomers plan to continue studying J0313-1806 and other quasars with terrestrial and space telescopes.