Astronomers have made the first ever observations of cosmic dust at the center of the Milky Way Galaxy. This dust has the ability to form new stars and was created by an ancient supernova. The findings, published in the journal Science, could help scientists understand exactly why there is so much dust in the galaxy.
"Dust itself is very important because it's the stuff that forms stars and plants, like the sun and Earth, respectively, so to know where it comes from is an important question," said Ryan Lau, lead author of the new study, in a news release."Our work strongly reinforces the theory that supernovae are producing the dust seen in galaxies of the early universe."
Why the galaxy is so dusty is one mystery that has yet to be unlocked by astronomers across the world. The leading theory is that supernovae contain large amounts of metal-enriched material that, in turn, harbors key ingredients of dust, like silicon, iron and carbon. These supernovae then emit this material as a dust that continues to travel throughout the galaxy. Lau said that when a supernova explodes, the materials in its center expand and form dust. This has been observed in several young supernova remnants - such as the famed SN1987A and Cassiopeia A.
For this latest study, researchers examined Sagittarius A East, which is a 10,000 year old remnant of a supernova near the center of our galaxy. When a supernova explodes, the materials in its center expand and form dust. In the often turbulent environment of a supernova, however, scientists expect the churning dust to be destroyed leading researchers to decide to directly observe the object.
To help them observe the supernova, researchers used the Faint object Infrared Camera Telescope (FORCAST) aboard the Stratospheric observatory for Infrared Astronomy (SOFIA). SOFIA, a modified Boeing 747, helped researchers achieve their goal allowing them to directly observe the supernova. Currently, no space-based telescope can observe at far-infrared wavelengths, and ground-based telescopes are unable to observe light at these wavelengths due to the Earth's atmosphere.
"There have been no direct observations of any dust surviving the environment of the supernova remnant...until now, and that's why our observations of an 'old' supernova are so important," said Lau.
But the direct observation of this cosmic dust is still a landmark discovery as it gives yet another clue into how our galaxy game together and continues to grow today.