Astronomers have seen the most energetic cosmic explosion, which they believe resulted from a cloud of gas disrupted by a supermassive black hole.
The burst (called AT2021lwx) happened billions of light-years away and was first seen in 2020. But now it lasted for more than three years, indicating a huge amount of material was involved in the event. The team’s research describing the eruption was published now in the Monthly Notices of the Royal Astronomical Society.
“Once you know the distance to the object and how bright it is to us, you can calculate the brightness of the object at its source,” said Sebastian Hönig, an astronomer at the University of Southampton and a co-author of the paper, in a university release. “Once we did those calculations, we realized it was very bright.”
The massive explosion dwarfs that of BOAT (or the Brightest of All Time), a gamma-ray burst seen last year. BOAT is still the brightest known explosion, but it is short-lived compared to the multi-year outburst of AT2021lwx.
The explosion is as bright as a quasar—an active galactic nucleus with a supermassive black hole at its core, which appears very bright in the sky. But unlike a quasar, AT2021lwx recently appeared in the sky. The team believes the event was caused by interactions between a cloud and a supermassive black hole.
Black holes are the densest objects in the universe. Their gravitational pull is so great that even light cannot escape their event horizons. Previously only the field of theory (these mysterious things were first predicted by Einstein), the shadows of black holes have already been imaged by large radio telescopeswhich indicates researchers at in the details of their extreme physics.
A recent astronomical team thinks the explosion was caused by stray gas (or dust) from a cloud orbiting the black hole, which fell into the superdense object. In our view, material is still falling into the black hole, but the explosion happened about 8 billion years ago.
“With new facilities, such as the Vera Rubin Observatory’s Legacy Survey of Space and Time, coming online in the next few years, we hope to discover more events like this and learn more about them,” said by Philip Wiseman, also an astronomer at the University of Southampton and the paper’s lead author, in the same release. “It may be that these events, although very rare, are so energetic that they are key processes in how the centers of galaxies change over time.”
The Legacy Survey of Space and Time will use the the world’s largest digital camera to image the night sky every 15 secondsgiving astronomers around the world a new dynamic view of the ever-changing universe.
The team plans to collect X-ray data on the explosion, among other wavelengths of light, to better understand the origins of the massive explosion.
More: What We Learned From the First Black Hole Image