This artist’s concept shows the amazing glow of two quasars located at the centers of two galaxies in a chaotic merger. The gravitational pull between two galaxies ignites the firestorm of star birth. Quasars are brilliant beacons of intense light from the centers of distant galaxies. They are powered by supermassive black holes that feed on infalling matter. This nurturing frenzy unleashes a stream of radiation that can outshine the collective light of billions of stars in the host galaxy. Over a few billion years, the black holes and their galaxies will merge to form a pair of quasars, an even larger black hole. Credit: NASA, ESA, and Joseph Olmsted (STScI)
A pair of merging galaxies ignite black holes on a collision course
Quasars are among the brightest in the universe. Dotted across the sky, it burns as richly as more than 100 billion stars. And just as the bright Fourth of July stretches across the sky, they shine for relatively short periods of time — on cosmic time scales. This is because they are powered by turbulent supermassive black holes that swallow copious amounts of gas and dust that heat up to high temperatures. But the quasar food buffet only lasts for so long.
This fast property of quasars enabled astronomers to detect two quasars colliding with each other. They are embedded in a pair of galaxies that collided 10 billion years ago. Such active twins are rare in the distant universe. The results provide clues to how unstable the universe was long ago, when galaxies collided frequently and black holes swallowed up debris and objects from close encounters.
Because the two quasars glow at different rates as their fuel fades and fades, they have been identified as an unusual process in space. The Hubble telescope zoomed in and clearly resolved the pair and their host galaxies.
Hubble Space Telescope image of a pair of quasars when the universe was only 3 billion years old. It is embedded in a pair of colliding galaxies. Quasars are separated by the size of less than a galaxy. Quasars are powered by supermassive, turbulent black holes that erupt ferocious fountains of energy as they entrap gas, dust, and just about anything else in their gravitational grasp. The black holes eventually merge. Credit: NASA, ESA, Yu-Ching Chen (UIUC), Hsiang-Chih Huang (IAS), Nadja Zakamska (JHU), Yu Chen (UIUC)
The Hubble Space Telescope has unexpectedly detected a double quasar in the distant universe
The early universe was a frantic place where galaxies frequently collided and merged together. Use[{”attribute=””>NASA’s[{”attribute=””>NASA’s
” data-gt-translate-attributes=”[{“attribute=””>HubbleSpaceTelescope[{“attribute=””>HubbleSpaceTelescope and other space and ground-based observatories, astronomers investigating these developments have made an unexpected and rare discovery: a pair of gravitationally bound quasars, both blazing away inside two merging galaxies. They existed when the universe was just 3 billion years old.
Quasars are bright objects powered by voracious, supermassive black holes blasting out ferocious fountains of energy as they engorge themselves on gas, dust, and anything else within their gravitational grasp.
“We don’t see a lot of double quasars at this early time in the universe. And that’s why this discovery is so exciting,” said graduate student Yu-Ching Chen of the University of Illinois at Urbana-Champaign, lead author of this study.
Finding close binary quasars is a relatively new area of research that has just developed in the past 10 to 15 years. Today’s powerful new observatories have allowed astronomers to identify instances where two quasars are active at the same time and are close enough that they will eventually merge.
There is increasing evidence that large galaxies are built up through mergers. Smaller systems come together to form bigger systems and ever larger structures. During that process there should be pairs of supermassive black holes formed within the merging galaxies. “Knowing about the progenitor population of black holes will eventually tell us about the emergence of supermassive black holes in the early universe, and how frequent those mergers could be,” said Chen.
This compass image shows a Hubble Space Telescope photograph of a pair of quasars that existed when the universe was just 3 billion years old. They are embedded inside a pair of colliding galaxies. The quasars are separated by less than the size of a single galaxy. Quasars are powered by voracious, supermassive black holes blasting out ferocious fountains of energy as they engorge themselves on gas, dust, and anything else within their gravitational grasp. The black holes will eventually merge. Credit: NASA, ESA, Yu-Ching Chen (UIUC), Hsiang-Chih Hwang (IAS), Nadia Zakamska (JHU), Yue Shen (UIUC)
We’re starting to unveil this tip of the iceberg of the early binary quasar population,” said Xin Liu of the University of Illinois at Urbana-Champaign. “This is the uniqueness of this study. It is actually telling us that this population exists, and now we have a method to identify double quasars that are separated by less than the size of a single galaxy.”
This was a needle-in-haystack search that required the combined power of NASA’s Hubble Space Telescope and the W.M. Keck Observatories in Hawaii. Multi-wavelength observations from the International Gemini Observatory in Hawaii, NSF’s Karl G. Jansky Very Large Array in New Mexico, and NASA’s Chandra X-ray Observatory also contributed to understanding the dynamic duo. And, ESA (