Determine whether wide explosion asymmetries are required

Determine whether the observed abundance ratios in the four ejecta clumps of MSH 15−52 require wide asymmetries in the supernova explosion, rather than being explainable within the current observational uncertainties by asymmetric explosion models without demonstrably wide asymmetries.

Background

The paper compares abundance measurements from four ejecta regions with asymmetric core-collapse supernova models for 15 and 25 solar-mass progenitors. Different ejecta clumps are best matched by different explosion energies, which may indicate asymmetry in the explosion.

However, the authors state that the existing observational uncertainties allow suitable fits over a broad range of explosion energies. Consequently, the present data do not establish whether broad or wide asymmetries are necessary, leaving this question unresolved pending improved observations and simulations.

References

However, suitable fits can occur over a wide range of explosion energies with the current observational uncertainties. With the current data, we cannot demonstrate wide asymmetries are needed, but as the data and simulations improve, data/simulation comparisons can place constraints on the explosion asymmetries.

— The Hand of God Revisited: Revealing the Shell Structure and Jet-Supernova Remnant Interaction in MSH 15-52  (2610.11813 - Dang et al., 8 Oct 2026) in Section 4.3, “Supernova Progenitor of MSH 15−52”