Researchers from the University of Copenhagen's Niels Bohr Institute and Aarhus University have successfully mapped out how cosmic dust formed after a gigantic supernova explosion.
Scientists have long wondered how cosmic dust is formed. One theory suggests supernova explosions produced cosmic dust, but the intensity and force of this particular explosion were so strong that the dust could not possibly survive. When the dust did, however, live through the violent explosion, researchers questioned the cosmic material even further.
Head of the Dark Cosmology Center at Niels Bohr Institute Professor Jens Hjorth and his colleagues collected observations of a supernova through an X-shooter located at the European Southern Observatory in Chile. The X-shooter was designed to be sensitive to at least three spectrographs of light, including ultraviolet light, infrared light and visible light.
The research team waited for a massive supernova to explode - one that was ten times brighter and 40 times more massive than the Sun. The team then analyzed the explosion for 2 ½ years and focused on the light emitted by a large explosion.
Project lead Christa Gall reported analysts discovered that the first step in the creation of cosmic dust was a mini-explosion, during which the star releases some amounts of carbon, helium, and hydrogen. These elements formed a gas shell that surrounded the star. As the star kept emitting the elements, the gas shell continued growing in size until it was large enough to protect itself from the explosion.
"When the star explodes, the shockwave hits the dense gas cloud like a brick wall. It is all in gas form and incredibly hot, but when the eruption hits the 'wall' the gas gets compressed and cools down to about 2,000 degrees," Gall explained.
At this temperature, she added, the elements would start forming a nucleate and would condense into a solid form. Dust grains were formed at this stage, as well as cosmic dust.
Further details of the study were published in the July 10 issue of Nature.
