The burst, named AT2022aedm, was observed by astronomers emerging from a red galaxy about 2 billion light-years from Earth using the ATLAS robotic telescope array located in Hawaii, Chile and South Africa. It was quickly recognized as something never seen before. Matt Nicholl, discovery team leader and astrophysicist at Queen’s, said: “We’re always looking for things that are a little strange and different from the standard types of supernovae where we find hundreds or even thousands every year.” . University of Belfast, told Space.com. “AT2022aedm stands out because it is one of the brightest explosions we have seen and also one of the fastest to die off after peak.” The explosion discovered by Nicholl and his team emitted 100 times more energy than an average supernova. Additionally, as supernovae fade over the months, Nicholl noted that AT2022aedm dropped to 1% of its original brightness after just 14 days, after which it disappeared completely. This means that in just two weeks, AT2022aedm emitted as much energy as the Sun during its 10 billion years of existence. Related: Black holes keep ‘burping’ stars they destroyed years ago, and astronomers don’t know why It’s no surprise that AT2022aedm sent shockwaves through the entire research team and earned itself a category of its own, as the scientists behind the discovery identified it as a “Rapid Cooler”. light” or “CFL” first.
I think the most promising explanation for LFCs like AT2022aedm lies in models involving the destruction of stars by black holes,” Nicholl explains. That’s the conclusion he and his colleagues reached by first eliminating several other prime suspects. Unusual suspects: how destructive black holes are One of the first steps taken by Nicholl and scientists at Queen’s University Belfast was to rule out some of the usual culprits of space disasters . The explosion didn’t look like a supernova because it was so powerful and so fast, but the location also helped distinguish this LFC as something completely new. One of the most common types of supernova is the core collapse supernova, which forms when giant stars more than eight times the mass of the sun run out of fuel for nuclear fusion. The cores of stars can no longer resist gravity and eventually collapse. This leaves a black hole or neutron star in the center of stellar debris from the star’s outer layers. “AT2022aedm cannot be a normal core-collapse supernova, because the galaxy in which it was observed has only old, low-mass stars; it has no more mass than eight times the mass of the sun, and that’s what you need.” to get a supernova,” Nicholl explains. Additionally, another common space explosion, a Type Ia supernova, occurs when stellar remnants called white dwarfs remove material from a companion star. This removal of matter causes the white dwarf to exceed the mass limit needed to trigger a supernova and create a neutron star or black hole, but these events produce a uniform amount of radiation. For this reason, astronomers call them “standard candles” and use them to accurately measure cosmic distances. However, the AT2022aedm doesn’t look like any of those things at all. This led the team to point the finger at black holes. But even then, they still try to eliminate the usual suspects.
Artist’s impression of a star interrupted as it passes near a supermassive black hole. (Image credit: ESO/M. Kornmesser) Supermassive black holes are wiped out. Events showing black holes tearing apart stars and then cannibalizing the remaining stars are rare but not unprecedented. Astronomers have discovered many examples of so-called “tidal disruption events” or “TDEs” as well as the light emitted during these violent processes. TDEs typically occur when a star gets too close to a supermassive black hole at the center of a galaxy. This black hole can have a mass millions or even billions of times the mass of our sun. The gravitational influence of these massive black holes creates enormous tidal forces in their target stars, stretching and compressing the stellar objects, tearing them to pieces in a process called “spaghettification”. “. However, Nicholl and his colleagues immediately understood that this LFC could not be the result of any TDA driven by a supermassive black hole. Again, this is partly due to LFC’s origins. Supermassive black holes are found at the centers of galaxies, and Nicholl said AT2022aedm was seen far from the center of its home galaxy. This means that a smaller black hole (not at the galactic center) could be the origin of this LFC. “If you have a lower-mass black hole in a dense environment with many stars and one of those stars comes very, very close to the black hole, even a stellar black hole 10 to 10 times more massive 100 times that black hole. black hole. Sun could still tear apart and destroy one of the stars,” he continued. Nicholl added that he and the team have yet to rule out a more intriguing suspect. It remains possible that the LFC is the product of an “intermediate-sized” or intermediate-mass black hole that lies between stellar-mass black holes and supermassive black holes ranging from 100 to several thousand times the size. of This is an exciting prospect, not only because intermediate-mass black holes remain elusive, but also because studying them could help explain how supermassive black holes develop. to such terrifying sizes early in the history of the universe. “Intermediate-mass black holes are thought to consume stars, and they are not necessarily at the center of stars,” said Nicholl. galaxies, because they may have been knocked out of their centers by a larger black hole.” “CFLs are likely related to intermediate-mass black holes, and if so, they would give us a new way to try to find and explain intermediate-mass black holes.
The team has made significant progress investigating the LFC, combing through archival data to find two “unsolved cases” corresponding to AT2022aedm, suggesting that this type of powerful cosmic explosion has previously observed but was buried in the data and perhaps missed. Nicholl’s next step is to study globular clusters, which are extremely dense groups of stars that can provide the conditions necessary for small or medium-sized black holes to destroy a star and trigger the LFC. Even if this research is successful, the astrophysicist’s joy of discovering something completely new will certainly not diminish. “We have been looking at the sky for a very long time and sometimes people think maybe we have seen everything there is,” Nicholl concludes. “I think things like this are really exciting because they remind us that the universe still has a lot of surprises in store for us, and when we build a new telescope, we will discover new thing and that will help us understand better.” our universe is better.” The team’s research was published in September. 1 in Astrophysical Journal Letters.
source:
https://iopscience.iop.org/article/10.3847/2041-8213/acf0ba/meta