Astrophysicists from different scientific organizations have observed a rare celestial event in which a supermassive black hole swallowed an entire star and released a bright hot flare made of matter.
In a study featured in the journal Science, an international team of researchers described how a star located around 300 million light-years away from the Solar System was sucked into a nearby black hole after succumbing to the powerful gravitational pull.
The event was then followed by the sudden release of a jet of plasma that came from the rim of the black hole.
Sjoert van Velzen, a researcher from the Johns Hopkins University and one of the authors of the study, explained that such events in space are very rare.
"It's the first time we see everything from the stellar destruction followed by the launch of a conical outflow, also called a jet, and we watched it unfold over several months," van Velzen said.
Black Holes In Space
According to scientists, black holes are pockets in space that have become so dense that an overwhelming force of gravity has formed and begun pulling in virtually anything in close proximity, including gas, matter and even light from stars. Once they are sucked into the void, these celestial objects are rendered invisible.
A theory among astrophysicists suggests that when a massive amount of gas, such as an entire star, is fed into a black hole, it would result in the ejection of elementary particles in the form of plasma jets emanating from the black hole's rim.
Van Velzen and his colleagues believe that the event they were able to observe serves to reinforce this assumption.
The supermassive black hole the researchers detailed in their study can be found at the lighter end of the spectrum for supermassive black holes. Despite having only a million times the mass of the Solar System's sun, the gigantic black hole still had enough gravitational force to suck in a whole star.
Destruction Of The Star
Researchers from the Ohio State University (OSU) were the first ones to witness the supermassive black hole gobble up the distant star. They announced their discovery through a Twitter post in December 2014.
After finding out about the OSU team's findings, van Velzen and other researchers from the University of Oxford in the United Kingdom carried out follow-up observations of the event using radio telescopes.
The international team was able to collect enough data on the event using ground-based telescopes and satellites to create a "multi-wavelength" image.
Van Velzen and his team first had to determine whether the light they witnessed originated from an expansive swirling mass known as an accretion disk that often occurs when matter is pulled into a black hole. This allowed them to verify that a newly-trapped star has indeed released the light from the distant galaxy.
Van Velzen pointed out that the ability of black holes to destroy whole stars is a very complicated process.
He said that their observations, such as the rapid formation of jets made from stellar debris, will help them formulate a more complete theory on such celestial events.
Importance Of Studying The Behavior Of Black Holes
Astronomy and physics professor Kelly Holley-Bockelmann of Vanderbilt University has been studying the formation of supermassive black holes for years. She has used computer simulations of black holes to find out how these celestial objects are capable of producing gravitational fields powerful enough to suck in even light.
In her studies, Holley-Bockelmann discovered that supermassive black holes play an important role in powering quasars that help create new galaxies in the universe, such as affecting the rate at which new stars are formed.
"Quasars are the enormously bright nucleus of a galaxy, and we think they're powered by the vigorous accretion of gas onto a supermassive black hole," Holley-Bockelmann said.
"This means that supermassive black holes must have evolved in a surprisingly short period. The question is, how did they grow so big so fast?"
Scientists have theorized that one of the most direct ways black holes develop is by sucking in massive amounts of dust and gas such as the star van Velzen and his colleagues were able to observe in their research.
When subjected to a black hole's powerful gravitational force, any dust particle or gas nearby is pulled into the void, forming a flattened disk around it known as an accretion disk.
The materials in the accretion disk are then heated and compressed, causing gas molecules and dust particles to collide repeatedly. While some materials begin to lose energy and spiral down into the black hole, others are able to build up enough energy to escape.
This theory, however, does not account for the speed at which black holes are able to develop. Despite being surrounded by an abundant supply of material, black holes have been found to take in only a certain amount of dust and gas at a time.
Another possible scenario involves the merger of two small black holes in order to create a massive one, but computer simulations have yet to reveal concrete proof of this theory. Scientists said a union of two powerful gravitational forces can often result in massive kicks that can cause them to sling out of a protogalaxy.
Holley-Bockelmann and other researchers are now exploring the possibility of the black holes using stars to produce an environment more suitable for such mergers.
The scientists believe black holes are able to shoot stars past each other in order to have them absorb some of the energy from their binary orbit. This would then allow the black holes to move closer together and eventually merge.
