Mapping the Nucleosynthetic Layers of Type Ia Supernovae with JWST featuring Lindsey Kwok (CIERA - Northwestern University)

Hosted by: Aldana Grichener  

Abstract: Type Ia supernovae (SNe Ia) are laboratories of explosive nucleosynthesis and major producers of the Universe’s iron-group elements, yet how the white dwarf explosion proceeds and the resulting nucleosynthetic yields remain uncertain. The spatial distribution of the explosion ashes records the density, burning regime, and geometry of the thermonuclear explosion, providing a means to distinguish among explosion models. JWST mid-infrared spectroscopy offers a uniquely clear view of the inner ejecta through comparatively isolated forbidden lines from key nucleosynthetic products, including stable nickel, radioactive cobalt, and intermediate-mass elements such as argon.

I will present late-time (nebular) JWST observations of a sample of normal and peculiar SNe Ia, using emission-line profiles from different ions to map distinct nucleosynthetic layers in the ejecta. The observed line morphologies reveal off-center explosions, variations in chemical stratification, and signatures of mixing and small-scale clumping. Together, these results demonstrate how JWST is transforming our view of SN Ia explosions by directly connecting the distribution of nucleosynthetic products to the physics of the explosion.

Website: lindseykwok.com