The highly-studied supernova remnant, Cassiopeia A, revealed more of its secrets in a recent 3D map of its interior taken by scientists.
The map is the "astronomical equivalent of a CAT scan," the Harvard-Smithsonian Center for Astrophysics reported. The findings showed the supernova remnant is filled with a suprising amount of bubbles.
"Our three-dimensional map is a rare look at the insides of an exploded star," said Dan Milisavljevic of the Harvard-Smithsonian Center for Astrophysics (CfA).
A massive star exploded about 340 years ago in the constellation Cassiopeia, causing an rapid stream of radioactive matter, The complex physics behind this phenomenon has been extremely difficult to model, even using "state-of-the-art" tools. Despite these roadblocks, researchers have worked to study young supernova remnants to gain insight what causes these spectacular explsions.
"We're sort of like bomb squad investigators. We examine the debris to learn what blew up and how it blew up," Milisavljevic said. "Our study represents a major step forward in our understanding of how stars actually explode."
To make the recent findings, a team of scientists created a 3D map in near-infrared wavelengths of light using the Mayall 4-meter telescope at Kitt Peak National Observatory. Spectroscopy allowed the researchers to measure the expansion velocities of dim material in the supernova's interior and uncover this key third dimension.
The map revealed giant interior cavities, or "bubbles," which could explain previously-observed rings of debris in the outer shell of Cas A. The most prominent cavities were determined to be between three and six light-years in diameter, and the entire supernova remnant was shown to have a Swiss cheese-like structure.
The researchers believe the bubbles were created by plumes of radioactive nickel created during the stellar explosion. Nickel eventually decays to form iron, and the bubbles are most likely enriched with as much as a tenth of a solar mass of iron. Further studies are needed to find this "missing" iron and confirm the source of the cavities.
The findings were published in a recent edition of the journal Science.
See the interactive map HERE.
