The universe is a dusty place; and the source of that dust seems to be supernovas.
Researchers believe dust from supernovas was significant in the early days of the universe, but until now little evidence to support that theory has been uncovered, a National Radio Astronomy Observatory news release reported.
A research team used the Atacama Large Millimeter/submillimeter Array (ALMA) telescope to observe the carcass of a late supernova that was "brimming with freshly formed dust," the news release reported.
"We have found a remarkably large dust mass concentrated in the central part of the ejecta from a relatively young and nearby supernova," Remy Indebetouw, an astronomer with the National Radio Astronomy Observatory (NRAO) and the University of Virginia, said. "This is the first time we've been able to really image where the dust has formed, which is important in understanding the evolution of galaxies."
The dusty supernova, dubbed 1987A, exists in the Large Magellanic Cloud (a dwarf galaxy that orbits the Milky Way at a distance of 168,000 light-years from Earth). The supernova got its name because its light first reached Earth in the year 1987.
Researchers had thought that as the gas produced during the explosion cooled it would form as atoms of "oxygen, carbon, and silicon." They believed these particles would bond together in the frigid center of the dead supernova. New observations reveal there was only a small amount of dust about 500 days after the initial explosion.
The team was able to image the cold dust because it glows in millimeter and submillimeter light. They found the remnant contains about "25 percent the mass of our Sun in newly formed dust." Carbon monoxide and silicon monoxide were also detected.
"1987A is a special place since it hasn't mixed with the surrounding environment, so what we see there was made there," Indebetouw said. "The new ALMA results, which are the first of their kind, reveal a supernova remnant chock full of material that simply did not exist a few decades ago."
Supernovas can create dust grains, but they can also destroy them.
The researchers determined that after the supernova exploded it released a "bright ring" of particles. When these materials hit the gas envelope they were "rebounded" back into the center of the dead supernova.
"At some point, this rebound shockwave will slam into these billowing clumps of freshly minted dust," Indebetouw said. "It's likely that some fraction of the dust will be blasted apart at that point. It's hard to predict exactly how much -- maybe only a little, possible a half or two thirds."
Dust that survived similar scenarios and entered interstellar space could account for the particles that researchers believe existed in the early days of the universe.
"Really early galaxies are incredibly dusty and this dust plays a major role in the evolution of galaxies," Mikako Matsuura of the University College London, said. "Today we know dust can be created in several ways, but in the early Universe most of it must have come from supernovas. We finally have direct evidence to support that theory."
