Nebular Phase Supernovae in 3D

by Mr Barteld van Baal (Stockholm University)

Friday 11 Apr 2025, 10:30 → 12:30 Europe/Stockholm

FC61 (AlbaNova Main Building)

The nebular phase of a supernova occurs several months to years after the explosion, when the ejecta become mostly optically thin yet there still is sufficient radioactive material to pump energy into the material. The asymmetries created by the explosion are encoded into the line profiles of the emission lines which appear in the nebular phase. Modern, 3D neutrino-driven core-collapse simulations have advanced enough that some models have been hydrodynamically modelled well past shock breakout, allowing us to fast-forward them into the nebular phase through homologeous expansion. Synthetic spectra of the nebular phase of core-collapse models can then be generated using the 3D NLTE Radiative Transfer code ExTraSS (EXplosive TRAnsient Spectral Simulator), which I developed during my PhD. Investigations can focus on how well the line profiles from 3D explosion models match the observed variations and to what degree viewing angles on the same angle are responsible for such variations, and how the synthetic spectra compare against observations. In this talk, I will cover the scientific background of supernovae and their nebular phase, the development of ExTraSS as 3D NLTE Radiative Transfer code, and showcase the results of a variety of core-collapse supernova models.