Properties of convective oxygen and silicon burning shells in supernova progenitors. Issue 2 (25th September 2017)

• Record Type: Journal Article
• Authors: Collins, Christine; Müller, Bernhard; Heger, Alexander
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 473:Issue 2(2018)
• Page Start: 1695
• Page End: 1704
• Publication Date: 2017-09-25
• Subjects: convection -- stars: evolution -- stars: massive -- supernovae: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stx2470
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: Recent 3D simulations have suggested that convective seed perturbations from shell burning can play an important role in triggering neutrino-driven supernova explosions. Since isolated simulations cannot determine whether this perturbation-aided mechanism is of general relevance across the progenitor mass range, we here investigate the pertinent properties of convective oxygen and silicon burning shells in a broad range of pre-supernova stellar evolution models. We find that conditions for perturbation-aided explosions are most favourable in the extended oxygen shells of progenitors between about 16 and 26 solar masses, which exhibit large-scale convective overturn with high convective Mach numbers. Although the highest convective Mach numbers of up to 0.3 are reached in the oxygen shells of low-mass progenitors, convection is typically dominated by small-scale modes in these shells, which implies a more modest role of initial perturbations in the explosion mechanism. Convective silicon burning rarely provides the high Mach numbers and large-scale perturbations required for perturbation-aided explosions. We also find that about 40 per cent of progenitors between 16 and 26 solar masses exhibit simultaneous oxygen and neon burning in the same convection zone as a result of a shell merger shortly before collapse.