Using data from the Japan-led Suzaku X-ray satellite, astronomers have determined measurements of debris suggest only a single white dwarf - not multiple white dwarfs - created a "crime scene" of debris.
"Mounting evidence indicates both of these mechanisms produce what we call type Ia supernovae," said lead researcher Hiroya Yamaguchi, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md., according to the press release. "To understand how these stars explode, we need to study the debris in detail with sensitive instruments like those on Suzaku."
The researchers analyzed archival observations of a supernova remnant named 3C 397, located about 33,000 light-years away in the constellation Aquila. Astronomers estimate this cloud debris has been expanding for 1,000 or 2,000 years.
NASA's Spitzer Space Telescope provided a infrared look at the expanding gas and dust the remnant has swept up. Since April 2005, 3C 397 has swept up a mass 18 times greater than the original white dwarf.
White dwarfs are the densest objects scientists know of, aside from neutron stars and black holes. Most stars similar to our sun will end as a white dwarf. A typical white dwarf is about the size of our Earth, but with the mass of our Sun.
"White dwarfs remain stable as long as they never tip the scales too closely to 1.4 solar masses," said Carles Badenes, assistant professor in the Department of Physics and Astronomy at the University of Pittsburgh in Pennsylvania, according to the press release. "White dwarfs near this limit are on the verge of a catastrophic explosion. All it takes is a little more mass."
"We can distinguish which of these scenarios is responsible for a given supernova remnant by tallying the nickel and manganese in the expanding cloud," said Goddard astrophysicist Brian Williams, according to the press release. "An explosion from a single white dwarf near its mass limit will produce significantly different amounts of these elements than a merger."
This study, which was published March 12 in The Astrophysical Journal Letters, is part of a continuing program of Suzaku research aimed at helping astronomers better understand the diversity of type Ia supernovae.
Reference:
"A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from the Enhanced Abundances of Nickel and Manganese," Hiroya Yamaguchi et al., Astrophysical Journal Letters, 2015 March 10, Vol. 801, No. 2, Let. 31 [https://iopscience.iop.org/2041-8205/801/2/L31, preprint: https://arxiv.org/abs/1502.04255].
