Astronomers have captured a supermassive black hole rip apart a wandering star and shoot out a spectacular jet – the first time the aftermath of a black hole destruction has been observed.
Scientists tracked the tidal disruption event (TDE) with radio and infrared telescopes in a pair of colliding galaxies called Arp 299 – some 150 million light-years from Earth – after they detected an infrared burst while searching for supernova explosions in 2005.
The team watched as a star more than twice the sun’s mass, drifted perilously close to a black hole 20 million times more massive than the sun. The star didn’t stand a chance against the gravitational force of the cosmic beast and was shredded to bits.
Radio-telescope images of Tidal Disruption Event in Arp 299 © Mattila, Perez-Torres, et al., B. Saxton NRAO/AUI/NSF
Only a small number of such stellar deaths have been detected, although scientists have suggested that they may be a more common occurrence. They have also theorised that after the star is obliterated, its material forms a rotating disk around the black hole and launches jets outward at nearly the speed of light. Until now, however, this has not been seen first hand.
“Never before have we been able to directly observe the formation and evolution of a jet from one of these events,” said study co-author Miguel Perez-Torres, of the Astrophysical Institute of Andalusia in Granada, Spain.
The team carried out observations for over 10 years and were ultimately rewarded with evidence of a jet.
“As time passed, the new object stayed bright at infrared and radio wavelengths, but not in visible light and X-rays,”said Seppo Mattila, of the University of Turku in Finland. “The most likely explanation is that thick interstellar gas and dust near the galaxy’s center absorbed the X-rays and visible light, then re-radiated it as infrared.”
“Because of the dust that absorbed any visible light, this particular tidal disruption event may be just the tip of the iceberg of what until now has been a hidden population,” Matilla added.
The team now hopes that similar observations of tidal disruption events can lead to a greater understanding of the formation and evolution of jets following black hole encounters.
