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Proposing Institution

Max Planck Institute for Astrophysics
Project Manager

Apl. Prof. Dr. rer. nat. Hans-Thomas Janka
Karl-Schwarzschild-Str. 1
85748 Garching
Core-collapse supernovae are among the most energetic events in the Universe with luminosities comparable to the brightness of a whole galaxy. They mark the violent, explosive death of massive stars, whose degenerate cores collapse to the most exotic compact objects known as neutron stars and black holes. In the proposed computational project (as extension of project pr53yi), the PI and his team plan to perform full-fledged three-dimensional (3D) supernova simulations to investigate a still unexplored problem in supernova physics. A novel hypothesis will be examined for explaining the origin of two mysterious, nearly opposing jet-like features in the Cassiopeia A supernova remnant, which contain silicon-rich but iron-poor ejecta and reach beyond the blast-wave shock with velocities of up to more than about 14,000 km/s. Replacing the standard assumption of a spherically symmetric pre-collapse structure of the progenitor star before its iron-core collapse by a more realistic 3D initial state of a ~19 solar-mass stellar model, the question will be investigated whether these wide-angle, high-velocity features could originate from violent mass motions of buoyant plasma in the convectively burning oxygen layer of the pre-collapse star. Such convective outflows and inflows were found to create large-scale asymmetries around the iron-silicon core in 3D simulations that the PI’s team performed during the previous phase of project pr53yi for the final 7 minutes before the ~19 solar-mass star begins to collapse. When the explosion sets in, the expansion of the SN shock will be massively affected by these pre-existing, radially very extended buoyant perturbations in the oxygen shell. One can imagine that this might lead to the acceleration of particularly fast silicon-rich material in the convective updrafts that contain the ashes of convective oxygen burning. This would naturally explain the silicon-richness of the highest-velocity ejecta in Cassiopeia A.

Impressum, Conny Wendler