Wednesday, 18 July, 2018

Goodbye, star. Astronomers first detected the star consumed a supermassive black hole

A NASA computer-simulated image of gas from a star getting swallowed by a black hole and gas ejecting at light-speed into space A NASA computer-simulated image of gas from a star getting swallowed by a black hole and gas ejecting at light-speed into space
Theresa Hayes | 17 June, 2018, 16:40

This supermassive black hole is reportedly 20 million times bigger compared to the sun, while the star is over twice as large as the sun. If a star is too close to the black hole, its huge gravity pulls it towards it and rips the star.

Astronomers have managed to directly image, for the first time ever, a star being chomped down by a supermassive black hole. It looks like a heavenly body emits a flash of light at the moment when it is torn apart by the gravitational field of a supermassive black hole.

"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", Seppo Mattila, a member of the team, said in a statement.

"Never before have we been able to directly observe the formation and evolution of a jet from one of these events", said astronomer Miguel Perez-Torres of the Astrophysical Institute of Andalusia in Granada, Spain. Since the researchers were hunting for supernovas in galactic mergers, they pointed their telescopes at Arp 299 and, sure enough, on January 30, 2005, they detected a source of bright infrared light nestled within one of the two galaxies.

Over the years, the researchers noted the object in question remained bright in infrared and radio light, but not in x-ray or visible wavelength of the spectrum.

Monitoring that space region with an worldwide network of radio telescopes, including the European Interferometry Network (EVN), for more than a decade, allowed scientists to see the flash detected at radio wavelengths expand in one direction at a speed of about 75,000 kilometers per second, a quarter of the speed of light.

Tidal disruption events are rare and occur about once every 10,000 years in a typical galaxy because its central black hole is not actively consuming any material and consequently, not give off any light.

"TDEs can provide us with a unique opportunity to advance our understanding of the formation and evolution of jets in the vicinities of these powerful objects", Dr. Perez-Torres said. She also noted that others might be quick to make assumptions in their own observations, but this paper demonstrates just how much work and how much time it took for the scientists to conclude they were spotting a TDE. Events such this one are more abundant in the distant universe due to galaxies evolving in earlier stages.

Infrared and radio waves are those emitted beyond the visible light spectrum.

They published their findings in the 14 June online issue of the journal Science.

The scientists tracked the event with multiple radio and infrared telescopes from across the world, including the Lovell Telescope at Jodrell Bank Observatory, working as part of the European Very Long Baseline Network (EVN). Data are archived at the Infrared Science Archive housed at IPAC at Caltech.