Astronomers find evidence of how ancient black holes became supermassive

A new study conducted by astronomers explained how ancient black holes can grow into enormous sizes.

By Carlo Inigo Monzon
October 21, 2019 16:56 +08

Astronomers found evidence that the corona of a black hole is what drives its evolution. Pictured: A composite X-ray (blue), radio (pink and green), and optical (orange and yellow) image of the galaxy Centaurus A is shown in this image from space. A broad band of dust and cold gas is bisected at an angle by opposing jets of high-energy particles blasting away from the supermassive black hole in the nucleus. The arcs of multimillion-degree gas appear to be part of a projected ring 25,000 light years in diameter. The size and location of the ring indicates that it may have been produced in a titanic explosion that occurred about ten million years ago. NASA

Researchers discovered new evidence that could explain how some black holes grew into enormous sizes. According to the researchers, a massive collision between galaxies may have affected how black holes devour the cosmic materials around them.

A new study published in the Astrophysical Journal Letters revealed the findings of a team of astronomers after observing a distant galaxy known as Messier 77 or NGC 1068. The researchers were able to complete their observations of the galaxy by using the Atacama Large Millimeter/submillimeter Array observatory in Chile.

According to their observations, NGC 1068 is a Seyfert galaxy, which means it has an active supermassive black hole sitting at its center. The researchers noted that the black hole was formed during the early years of the universe. For the researchers, this period was too early for cosmic objects to grow into really enormous sizes.

Upon closer inspection, the researchers noticed that the black hole is surrounded by clouds of cosmic materials that are rotating in opposite directions. These counter-rotating clouds of gas, dust and other cosmic debris fall into the black hole. The researchers explained that the opposing direction of the rotating clouds enables the black hole to consume cosmic materials at a much faster rate, causing it to become enormous. According to the researchers, the black hole is about 15 million times more massive than the Sun.

Black hole devouring a star — For the first time, NASA’s planet-hunting Transiting Exoplanet Survey Satellite (TESS) watched a black hole tear apart a star from start to finish, a cataclysmic phenomenon called a tidal disruption event. The blast, named ASASSN-19bt, was found on Jan. 29 by the All-Sky Automated Survey for Supernovae (ASAS-SN), a worldwide network of 20 robotic telescopes. Shortly after the discovery, ASAS-SN requested follow-up observations by NASA’s Swift satellite, ESA’s (European Space Agency’s) XMM-Newton and ground-based 1-meter telescopes in the global Las Cumbres Observatory network NASA Goddard

"Surprisingly, we found two discs of gas rotating in opposite directions," Violette Impellizzeri, the lead author of the study, said in a statement. "Counter-rotating gas streams are unstable, which means that clouds fall into the black hole faster than they do in a disk with a single rotation direction. This could be a way in which a black hole can grow rapidly."

Jack Gallimore, an astronomer from Bucknell University and co-author of the study, said that counter-rotating clouds around black holes are not very common. He theorized that these may have been formed following a violent collision between NGC 1068 and another galaxy. The collision may have disturbed the cosmic materials inside the galaxy, causing them to rotate in an unorthodox manner.

"The counter-rotation always results from the collision or interaction between two galaxies," he explained. "What makes this result remarkable is that we see it on a much smaller scale, tens of light-years instead of thousands from the central black hole."