The light of these two quasar pairs comes to us from a time when the universe was about 10 billion years old. A quasar’s energy is thought to be created when a supermassive black hole furiously feeds on infalling matter. Quasars are thought to lie at the hearts of young galaxies in the early universe. Thus we see them at a time when the universe was young, and so they can help reveal conditions in the early cosmos. Quasars have such astounding brilliance that they can be seen across vast reaches of the universe. That’s very close on a cosmic distance scale by comparison, our sun is about 26,000 light-years from the supermassive black hole at the center of our Milky Way galaxy.Ī quasar is an object in the distant universe that produces prodigious amounts of energy. Astronomers deduced that the blinking light is a telltale sign of the presence of two quasars and not a single object.Įach of the two newly discovered pairs of quasars – or four total quasars – were discovered within 10,000 light-years of their mate. The video simulation above shows the brilliant, flickering light from a pair of quasars. Finally, the team of scientists used the Hubble Space Telescope to image four candidates, two of which turned out to be close pairs of quasars. The scientists compared the alternating brightness between the quasar pair, as seen in the video above, to that of the dual blinking lights at a railroad crossing. Because quasars vary in brightness depending on how much material the black hole is consuming at the time, they produce a slight flickering appearance. Gaia is able to detect slight jiggles in the movement of the distant quasars. Then they used data from the Gaia Observatory to pin down the locations. To find the quasar pairs, astronomers pored over 3D maps from the Sloan Digital Sky Survey to find double-quasar candidates. The study was published April 1, 2021, in the peer-reviewed journal Nature Astronomy. As lead researcher Yue Shen of the University of Illinois at Urbana-Champaign put it:įinding these double quasars is like finding a needle in a haystack.Ī collaboration between scientists and some of the best telescopes in the world led to new images of the double quasars. They used a series of telescopes that led them from one step to the next, in a methodical unraveling of the mystery of which bright, apparently single quasars might actually be double. The astronomers would tell you, though, that they didn’t use luck. Astronomers estimate that only one in 1,000 quasars is double, so finding two double quasars could be seen as lucky. Each pair is thought to reside in the midst of two merging galaxies in the very distant universe. Astronomers said on April 6, 2021, that they’ve spotted two rare double quasars.
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