07/15/2024 | Press release | Distributed by Public on 07/15/2024 10:00
July 15, 2024, Mountain View, CA -- The SETI Institute announced the latest findings from the James Webb Space Telescope (JWST) of the supernova remnant, Cassiopeia A (Cas A). These observations of the youngest known core collapse supernova in the Milky Way provide insights into the conditions that lead to the formation and destruction of molecules and dust within supernova ejecta. The study's findings change our understanding of dust formation in the early universe in the galaxies detected by JWST 300 million years after the Big Bang. Researchers consider supernovae, such as those that formed Cas A, vital sources of the dust seen in distant, high-redshift galaxies. These new insights challenge beliefs that dust primarily originated from intermediate-mass stars on the asymptotic giant branch (AGB) in present-day galaxies.
"It is remarkable to see how bright the carbon monoxide emission detected in JWST NIR imaging and spectroscopy, showing a few tens of sinusoidal patterns of CO fundamental rovibrational lines," said Dr. Jeohghee Rho, research scientist at the SETI Institute who led this research. "The patterns look like they were artificially generated."
Key findings include:
"To see such hot CO in a young supernova remnant is truly remarkable and indicates that CO formation is still happening thousands of years after the explosion," said Chris Ashall, Assistant Professor at Virginia Tech. "Combining such impressive data sets with earlier JWST observations of supernovae will allow us to understand the pathway to molecules and dust formation in a way not previously possible."
The observations utilized JWST's Near Infrared Camera Instrument (NIRCam) and the Mid Infrared Instrument (MIRI), along with detailed Near-Infrared Spectrograph (NIRSpec)-Integral Field Units (IFU) spectroscopy. The team mapped the intricate structures of synchrotron radiation (light emitted when charged particles, like electrons, are sped up into high speeds in strong magnetic fields), argon-rich ejecta, and carbon monoxide (CO) molecules within Cas A. The images show very detailed and intricate patterns of shells, holes and filaments, highlighting how powerful JWST is.
Seong Hyun Park, a graduate student at Seoul National University in South Korea, performed modeling of the CO properties together with Rho.
The new observations highlight supernova remnants' complex and competing molecular formation and destruction processes. While not directly leading to dust formation, CO molecules are critical indicators of the cooling and chemical processes that eventually lead to dust condensation.
While this study offers new perspectives, the debate continues regarding the extent to which supernovae contribute to dust formation in the early universe. Researchers will continue exploring these phenomena with future observations and research to unravel the mysteries of cosmic dust and molecular formation.
The findings are published this week in the Astrophysical Journal as a Letter.
JWST three-color image of synchrotron, CO, and Ar emission has been featured as a cover image in NOVA at:
Featured Image: A New Portrait of Cassiopeia A
Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization whose mission is to lead humanity's quest to understand the origins and prevalence of life and intelligence in the Universe and to share that knowledge with the world. Our research encompasses the physical and biological sciences and leverages expertise in data analytics, machine learning and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia and government agencies, including NASA and NSF.
Contact information
Rebecca McDonald
Director of Communications
SETI Institute
[email protected]