JWST Spectroscopy Reveals New Details About Type Ia Supernovae Explosion Mechanisms
New observations from the James Webb Space Telescope of two Type Ia supernovae show evidence of enhanced nickel abundance in their cores and characteristics consistent with a deflagration-to-detonation explosion mechanism. The findings come from detailed spectroscopic analysis spanning infrared wavelengths from 0.35 to 28 microns in the nebular phase of the supernovae. These results demonstrate that JWST's capabilities can now resolve fine details in supernova ejecta that constrain explosion models and progenitor properties.
Researchers analyzing JWST observations of Type Ia supernovae 2022aaiq and 2024gy detected narrow cores in nickel emission lines that indicate enhanced stable nickel abundance in the central regions of these explosions. The spectroscopic data, spanning optical through mid-infrared wavelengths, revealed spatially distinct zones of different elemental compositions and a distinctive "broken-slope" morphology in iron-group element emission that matches predictions for delayed detonation models. By comparing stable nickel luminosities across multiple supernovae, the team inferred that SN 2024gy likely originated from a near-Chandrasekhar-mass white dwarf progenitor, while SN 2022xkq appears to have come from a lower-mass progenitor. The resolved line profiles now accessible with JWST provide unprecedented diagnostics of explosion geometry, central density, and progenitor mass in Type Ia supernovae, advancing understanding of these important cosmic distance markers.
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- arXiv astro-phCenter
JWST Spectroscopy of SN Ia 2022aaiq and 2024gy: Evidence for Enhanced Central Stable Ni Abundance and a Deflagration-to-Detonation Transition
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