It’s a dog-eating universe. Less than two weeks ago, on May 3, astronomers reported that they had observed a star in the process of devouring one of its own planets. Just two days earlier, another team described Black holes are ripping apart stars and consuming them in a process known as a tidal discontinuity event, or TDE
Now, an international team of astronomers reports that they are observing one of the most violent and powerful acts of cannibalism ever witnessed, perhaps the largest explosion ever seen in history. cosmic history. Eight billion light-years from Earth, in the darkness beyond the constellation Vulpecula, a black hole perhaps a billion times more massive than the sun appears to be gobbling up a giant cloud of gas. A study of the phenomenon appears on Fridays in the Monthly Notices of the Royal Astronomical Society.
Research began on April 13, 2021, when the Zwicky Transient Facility, a small telescope busy searching for exploding stars or supernovas, detected a flash of light that did not match expectations. wait. Most supernovae fade after a few weeks; this one, called the AT2021lwx, continues — and has continued to boom for three years now.
In fact, the explosion turned out to have been first detected a year earlier by the Terrestrial Asteroid Impact Last Warning System, or ATLAS, a network of robotic telescopes in Hawaii, South Africa and Chile. That was the real beginning of the cataclysm; As it happened, a worldwide network of telescopes and satellites tracked it, measuring its emission across the electromagnetic spectrum, from high-energy X-rays to infrared.
“Most supernovas and tidal disruption events last only a few months before disappearing,” said Philip Wiseman, an astrophysicist at the University of Southampton and lead author of the new paper. “For something bright for more than two years at once is very unusual.”
What happen? Matt Nicholl of Queen’s University Belfast, who helped analyze the ongoing explosion, said: “At first, we thought this outburst could be the result of a black hole swallowing a star away. through. “But our models show that the black hole must swallow up to 15 times the mass of our sun to maintain its luminosity for such a long time.”
Another idea is that it was an explosion from a quasar – energy spewing from the edge of a supermassive black hole at the center of a galaxy. But there are no records of previous quasar activity at that site, nor are there any clear signs of a galaxy there.
Of the many uncertain explanations, the most likely, Dr Wiseman and his colleagues concluded, is that a black hole as massive as a billion suns is enjoying a long party over a cloud of clouds. giant gas cloud. They have encouraged colleagues to be wary of similar events.
Dr Wiseman said in an email: “AT2021lwx is an extraordinary event that does not fit into any of the usual temporal categories. He added that, with a total radiant energy equivalent to 100 supernovae, “it is one of the brightest stars ever detected.”
The recoil, that would put it in the group of colliding black holes. Dr Wiseman writes: “Colliding black holes release energy in the form of gravitational waves at extremely high luminosity – 10 billion times ‘stronger’ than this explosion. “But that power only lasts for 20 milliseconds,” adding that the explosion had lasted for years.
