Rare Blast’s Remains Discovered in Milky Way Center
Astronomers may have found our galaxy’s first example of an unusual kind of stellar explosion. This discovery, made with NASA’s Chandra X-ray Observatory, adds to the understanding of how some stars shatter and seed the universe with elements critical for life.
on Earth.
Credit: Chandra X-ray Observatory.
Data from Chandra have revealed that Sgr A East, however, did not come from an ordinary Type Ia. Instead, it appears that it belongs to a special group of supernovae that produce different relative amounts of elements than traditional Type Ias do, and less powerful explosions. This subset is referred to as “Type Iax,” a potentially important member of the supernova family.
“While we’ve found Type Iax supernovae in other galaxies, we haven’t identified evidence for one in the Milky Way until now,” said Ping Zhou of Nanjing University in China, who led the new study while at the University of Amsterdam. “This discovery is important for getting a handle of the myriad ways white dwarfs explode.”
Astronomers are still debating the cause of Type Iax supernova explosions, but the leading theory is that they involve thermonuclear reactions that travel much more slowly through the star than in Type Ia supernovae. This relatively slow walk of the blast leads to weaker explosions and, hence, different amounts of elements produced in the explosion. It is also possible that part of the white dwarf is left behind.
Image credit: X-ray: NASA/CXC/Nanjing Univ./P. Zhou et al. Radio: NSF/NRAO/VLA
Sgr A East is located very close to Sagittarius A*, the supermassive black hole in the center of our Milky Way galaxy, and likely intersects with the disk of material surrounding the black hole. The team was able to use Chandra observations targeting the supermassive black hole and the region around it for a total of about 35 days to study Sgr A East and find the unusual pattern of elements in the X-ray data. The Chandra results agree with computer models predicting a white dwarf that has undergone slow-moving nuclear reactions, making it a strong candidate for a Type Iax supernova remnant.
“This supernova remnant is in the background of many Chandra images of our galaxy’s supermassive black hole taken over the last 20 years,” said Zhiyuan Li, also of Nanjing University. “We finally may have worked out what this object is and how it came to be.”
In other galaxies, scientists observe that Type Iax supernovae occur at a rate that is about one third that of Type Ia supernovae. In the Milky Way, there have been three confirmed Type Ia supernova remnants and two candidates that are younger than 2,000 years, corresponding to an age when remnants are still relatively bright before fading later. If Sgr A East is younger than 2,000 years and resulted from a Type Iax supernova, this study suggests that our galaxy is in alignment with respect to the relative numbers of Type Iax supernovae seen in other galaxies.
Along with the suggestion that Sgr A East is the remnant from the collapse of a massive star, previous studies have also pointed out that a normal Type Ia supernova had not been ruled out. The latest study conducted with this deep Chandra data argue against both the massive star and the normal Type Ia interpretations.
These results have been published today in The Astrophysical Journal, and a preprint is available online. The other co-authors of the paper are Ken’ichi Nomoto of The University of Tokyo in Japan, Jacco Vink of the University of Amsterdam in The Netherlands, and Yang Chen, also of Nanjing University.
NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.
Contacts and sources:
Lee Mohon NASA Marshall Space Flight Center
Publication: Chemical abundances in Sgr A East: evidence for a Type Iax supernova remnant.
Ping Zhou, Shing-Chi Leung, Zhiyuan Li, Ken’ichi Nomoto, Jacco Vink, Yang Chen. The Astrophysical Journal, 2021 [abstract]
Please Donate Below To Support Our Ongoing Work To Expose The Lies About COVID19
PRINCIPIA SCIENTIFIC INTERNATIONAL, legally registered in the UK as a company 
incorporated for charitable purposes. Head Office: 27 Old Gloucester Street, London WC1N 3AX.
Please DONATE TODAY To Help Our Non-Profit Mission To Defend The Scientific Method.
Trackback from your site.