In just a few weeks, two papers were published describing the AT2021lwx, also known as ZTF20abrbeie, by two independent groups. Probably more famous by the nickname “Terrible Barbie”, this event stands out as the largest cosmic explosion ever detected.
The first study, published last week, suggested that this explosion was a star being torn apart by a supermassive black hole, in an event described as a gravitational fragmentation event. Barbie is notable for being three times brighter than the brightest shot fragmentation event ever recorded. The second paper argues that if the supermassive black hole smashed a star about 15 times the mass of the Sun, it instead devoured a larger gas cloud that was about 1,000 times heavier than our Sun.
From Queen University Belfast, Dr. “At first we thought this flare could be the result of a black hole consuming a passing star,” said Matt Nicholl. But our models showed that for the black hole to stay this bright for so long, it would have to swallow up to 15 times the mass of our Sun.” “Many massive black holes are surrounded by gas and dust, and we’re still trying to figure out why this black hole started feeding so violently and suddenly.”
It also draws attention with its duration: Exactly 3 years!
Barbie draws attention not only with the energy emanating from the event, but also with its duration. Supernova or gravitational fragmentation events only stay visible for a few months and are usually not that bright. The Barbie boom lasted for three years. Even transient events that can be this bright, such as the brightest recent gamma-ray burst GRB 221009A (which was even brighter), last not years but minutes.
The only other objects approaching these values are quasars, a state of supermassive black holes that begin to be fed tremendously by a steady stream of gas. These beings are the brightest objects in the universe.
University of Southampton Professor Mark Sullivan, one of the paper’s co-authors, said in a statement: “When we look at a quasar, we see that the luminosity rises and falls over time. “But looking back over a decade, there was no detection of the AT2021lwx, then suddenly it appeared with the brilliance of the brightest things in the universe, which was unprecedented.”
Observations of the Terrifying Barbie explosion, which may perhaps be the beginning of a quasar phase, continue, and so it can be predicted that we will see more research on this remarkable cosmic event in the years to come.
The study was published in Monthly Notices of the Royal Astronomical Society…