2018/01/31 by Roni Anna Gofman, Avishai Gilkis, Noam Soker
Physics and Astronomy · #Astro and Planetary Science #Astrophysics #Atomic physics #Gamma-ray bursts and supernovae #Helium #Nuclear physics #Nuclear reaction #Nucleosynthesis #Physics #Plasma #Shell (structure) #Stars #Stellar evolution #Stellar, planetary, and galactic studies #Supernova #Thermonuclear fusion #Type II supernova #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1093/mnras/sty1078
will be submitted in a few days to allow comments by readers. new version after comments by the referee
arxiv created 2018/04/01 · openalex publication_date 2018/04/26 · arxiv updated 2018/05/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We evolve models of rotating massive stars up to the stage of iron core collapse using the mesa code and find a shell with a mixed composition of primarily helium and oxygen in some cases. In the parameter space of initial masses of 13–40 M⊙ and initial rotation velocities of 0–450 km s−1 that we investigate, we find a mixed helium–oxygen (He-O) shell with a significant total He-O mass and with a helium to oxygen mass ratio in the range of 0.5–2 only for a small fraction of the models. While the shell formation due to mixing is instigated by rotation, the pre-collapse rotation rate is not very high. The fraction of models with a shell of He-O composition required for an energetic collapse-induced thermonuclear explosion is small, as is the fraction of models with high specific angular momentum, which can aid the thermonuclear explosion by retarding the collapse. Our results suggest that the collapse-induced thermonuclear explosion mechanism that was revisited recently can account for at most a small fraction of core-collapse supernovae. The presence of such a mixed He-O shell still might have some implications for core-collapse supernovae, such as some nucleosynthesis processes when jets are present, or might result in peculiar sub-luminous core-collapse supernovae.