Astronomers have detected the most powerful cosmic explosion ever seen: a mysterious, years-long eruption 10 times brighter than any observed supernova.
The astronomers detected the event, called AT2021lwx, 8 billion light-years from Earth. Releasing roughly 100 times the energy the sun will release in its lifetime, the strange explosion kicked into action when the universe was 6 billion years old.
“We came across this by chance, as our search algorithm flagged it when we were looking for a type of supernova,” said the study’s lead author. philip wise (opens in a new tab)astronomer at the University of Southampton in the UK, said in a statement (opens in a new tab). “Most supernovae and tidal disruption events [bright flashes that occur when black holes tear apart wandering stars] it only lasts a couple of months before it wears off. For something to be shiny for more than two years was immediately very unusual.”
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The cause of the mysterious explosion is unclear, but astronomers believe it is more likely the result of a gigantic cloud of hydrogen gas thousands of times larger than our sun being engulfed by a supermassive. black hole.
As chunks of the cloud are swallowed, shock waves travel through the remaining hot gas, producing a giant explosion whose light has been bombarding Earth for more than two years and has yet to die out. Using two telescope systems designed for full-sky surveys, the Zwicky Transient Facility in California and the Asteroid Land-impact Last Alert System (ATLAS) in Hawaii, the researchers detected the bright, flickering light from the distant event.
Black holes are born from the collapse of giant stars and grow by gorging themselves on gas, dust, stars and other black holes. For some of these gluttonous ruptures of space-time, friction causes the material spiraling into their maw to heat up and emit light that can be detected by telescopes, turning them into so-called active galactic nuclei (AGNs).
The most extreme AGNs are quasars: supermassive black holes billions of times heavier than the sun that shed their gaseous cocoons with bursts of light trillions of times more luminous than the brightest stars.
However, despite being bright on the scale of a quasar, the explosion is too brief to be so.
“With a quasar, we see the brightness flickering up and down over time. But looking back for a decade, there was no detection of AT2021lwx, then suddenly it appears as bright as the brightest things in the universe, which which is unprecedented”, co-author mark sullivan (opens in a new tab), professor of astronomy at the University of Southampton, said in the statement. This means that the explosion likely came from a gas cloud that was initially safely orbiting the black hole, but veered off course to be sucked into the jaws of the cosmic monster.
To confirm the identity of the object causing the explosion, the researchers are now studying the explosion in more detail by scanning across wavelengths. This could reveal its surface shape, temperature, and the mysterious processes that generate the glowing light.
The researchers published their findings May 11 in the journal Monthly Notices of the Royal Astronomical Society (opens in a new tab).