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This ultra-rare quasar pair could help explain how galaxies evolve

todayApril 13, 2021 2

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Quasars are found throughout the Universe, but quasar pairs are rare.

“We estimate that in the distant universe, for every 1,000 quasars, there is one double quasar. So finding these double quasars is like finding a needle in a haystack,” Dr. Yue Shen of the University of Illinois Urbana-Champaign, explains.

These newly-recognized pairs are the oldest of the 100 or so quasar pairs currently known to astronomers.

The quasar pairs examined in this study are seen as they were the distant past, less than four billion years after the Big Bang. As the quasars drifted toward each other, energy would have raced from the bodies, radiating into space. Eventually, the quasars would have merged into single black holes of enormous size.

Analysis of the study was published in Nature Astronomy.

Two quasar pairs seen in the early Universe are the oldest, most-distant bodies objects of their kind yet seen in the Cosmos.

Quasars are extremely energetic galaxies, powered by highly-active supermassive black holes near their centers. Matter falling into the behemoth void in the galactic core radiates vast amounts of energy out to space, forming a quasar. While this process is active, these supermassive black holes can outshine entire galaxies.

The quasars in each pair examined in this new study are just 10,000 light years from each other. This may sound like quite a distance, but this is just one-tenth the distance from one side of our galaxy to the other. This proximity suggests the quasars are found within merging galaxies.

“This truly is the first sample of dual quasars at the peak epoch of galaxy formation that we can use to probe ideas about how supermassive black holes come together to eventually form a binary,” explained Dr. Nadia Zakamska of Johns Hopkins University.

Paring down the pairs

Credit: NASA, ESA, H. Hwang and N. Zakamska (Johns Hopkins University), and Y. Shen (University of Illinois, Urbana-Champaign)